“Strep throat” is acute tonsillopharyngitis caused by Streptococcus pyogenes (group A β-hemolytic streptococci [GABHS]) in the majority, and occasionally by serogroups C and G. Strep throat is seen among schoolchildren (5–15 years) with a peak incidence during the first few years of school. The incubation period is 2 to 4 days. Presenting symptoms are abrupt onset with high fever, sore throat, pain on swallowing, malaise, headache, and abdominal pain. Pharynx is beefy red; palate and uvula may be edematous, reddened, and covered with petechiae. Tonsils are erythematous, enlarged with patches of a gray-white exudate giving a “strawberry” appearance (intensity of exudates either absent in mild cases to distinct membrane covering entire pharynx in severe cases). Tender anterior cervical lymphadenopathy at the angles of the mandibles is palpable.
Figure 3.1 ▪ Exudative Tonsillopharyngitis.
Exudative tonsillopharyngitis in an adolescent presenting with high fever, sore throat, and tender anterior cervical adenopathy and a throat culture positive for GABHS. Intensity of exudates can be absent in mild cases to formation of a membrane covering the entire pharynx in severe cases. (Photo contributor: Mark Silverberg, MD.)
Scarlet fever rash may appear 12 to 24 hours after the onset of fever. The patient’s forehead and cheeks are flushed with circumoral pallor and a rash of tiny papules that appears like a “sunburn with goose pimples,” has the texture of sandpaper, and blanches prominently with pressure. The rash begins in the axilla, groin, and neck and generalizes, sparing the palms, soles, and face within 24 hours. Other findings include strawberry tongue, exudative tonsillopharyngitis, and Pastia sign (an accentuation of the rash in skin folds with fine line of petechiae). Desquamation may occur after 7 to 10 days and usually continues for 2 to 3 weeks, but can last up to 2 months. When desquamation occurs, it begins as fine flakes on the face, then precedes over the trunk, hands, and feet. The extent and duration of desquamation are directly related to the intensity of the rash. Scarlet fever rash is caused by one or more of several erythrogenic exotoxins produced by GABHS strains and occurs in children who lack the immunity to the exotoxin. The portal of entry is oropharynx in the majority and rarely a surgical wound (surgical scarlet fever). Most cases occur in children between 2 and 8 years of age in winter and early spring.
Both streptococcal pharyngitis and scarlet fever are self-limited diseases. Fever abates within 3 to 5 days (in absence of suppurative complications) with resolution of all signs and symptoms within 1 week. Tonsillar hypertrophy and lymph nodes take several weeks to return to their usual size. Suppurative complications include acute cervical lymphadenitis, peritonsillar cellulitis or peritonsillar abscess, retropharyngeal abscess, acute otitis media, acute sinusitis, mastoiditis, pneumonia, toxic shock syndrome (TSS), intracranial complications (eg, meningitis, brain abscess), bacteremic spread with metastatic infection (eg, septic arthritis, osteomyelitis), and nonsuppurative complications include acute rheumatic fever (ARF) and acute glomerulonephritis. Differential diagnosis of exudative tonsillopharyngitis includes viral infections (eg, adenovirus, Epstein-Barr virus, herpes simplex virus [shallow tonsillar ulcers with gray exudates), other bacteria (diphtheria, tularemia), and Candida (immunosuppressed patients). Differential diagnosis of scarlet fever includes Kawasaki disease, staphylococcal scarlatina, staphylococcal scalded skin syndrome, viral exanthems, mycoplasma infection, TSS, drug hypersensitivity reactions, severe sunburn, and Arcanobacterium haemolyticum infection (tonsillopharyngitis with scarlatiniform rash; seen in adolescents and young adults).
Figure 3.3 ▪ Scarlet Fever.
(A) Erythematous scarlatiniform rash with sore throat and fever were seen in this child. Note the prominence of the rash in the neck, axillas, and groin (all pressure sites). (B) In dark-skinned patients, the scarlet fever rash may be palpated more easily as “sandpaper texture” than seen. Note the accentuation of the rash in the neck area and absence of conjunctival injection and red lips (characteristic features of Kawasaki disease that also presents with scarlatiniform rash). (Photo contributors: Bipin Patel MD [A] and Binita R. Shah, MD [B].)
Confirm diagnosis by either performing a throat culture (vigorously swab tonsils and posterior pharynx to obtain an adequate sample) or rapid antigen detection test as accurate clinical differentiation of viral and GABHS pharyngitis is not possible. A positive rapid antigen test is diagnostic; a negative test requires a throat culture. Consider starting therapy after a positive rapid antigen detection test; withholding therapy for 24 to 48 hours while awaiting throat culture results does not increase the risk of ARF. Prescribe antibiotics (before throat culture result) for patients with any of the following: prior history of ARF, scarlet fever, suppurative complications (eg, peritonsillar cellulitis or abscess), or patients unavailable for follow-up. Prescribe penicillin V (drug of choice) orally for 10 days (emphasize the importance of completing the full 10-day course regardless of clinical improvement to prevent ARF). If compliance is an issue, alternatives include amoxicillin (single daily dose for 10 days) or benzathine penicillin G (BPG) or mixtures of BPG with procaine penicillin (to reduce pain) given intramuscularly as a single dose. For patients allergic to penicillin, clarithromycin, azithromycin, or clindamycin are alternatives. Children can return to school after 24 hours of antibiotic therapy. Routine posttreatment follow-up culture is not needed.
Figure 3.4 ▪ “Strawberry Tongue” of Scarlet Fever.
(A) White strawberry tongue (edematous red papillae projecting through white-coated tongue is seen on the second day of illness in a child with scarlet fever). (B) The real “red strawberry tongue”? (C) Red strawberry tongue (as white coating disappears, red tongue is seen studded with prominent papillae that stand out). Other differential of strawberry tongue includes Kawasaki disease and toxic shock syndrome (TSS; Staphylococcus aureus–mediated TSS and Streptococcal-mediated TSS). (Photo contributor: Binita R. Shah, MD.)
Figure 3.6 ▪ Desquamation as Presenting Sign of Scarlet Fever.
This child was brought to emergency department because of this prominent (and frightening to parents) desquamation seen in both hands and lower extremities. He had a sore throat and low-grade fever with “goose bumps” 9 days before this finding. Desquamation may be a presenting sign of scarlet fever (if the initial acute phase is mild and overlooked). Large sheaths of epidermis may be shed from the palms and soles in a glove-like pattern, exposing new and tender epidermis beneath. (Photo contributor: Binita R. Shah, MD.)
Most common clinical illness produced by GABHS is acute tonsillopharyngitis.
Coryza, cough, conjunctivitis, hoarseness, diarrhea, discrete ulcers, or stomatitis in a child with pharyngitis strongly suggests a viral etiology and not GABHS infection.
Exudative pharyngitis in children <3 years of age is rarely of streptococcal etiology and diagnostic studies for GABHS are not recommended routinely.
Scarlet fever occurs most commonly in association with pharyngitis and rarely with pyoderma or an infected wound. Tonsillopharyngitis is absent in surgical scarlet fever.
Skin tenderness is absent in scarlet fever, as opposed to the prominent skin tenderness of staphylococcal scarletina.
Impetigo is a contagious superficial skin infection occurring in two forms: bullous and nonbullous (accounts for >70% of cases). Bullous impetigo is caused by Staphylococcus aureus, whereas the nonbullous form is caused by either group A β-hemolytic streptococcus (GABHS or S pyogenes), S aureus or both. Nonbullous impetigo is most commonly seen in preschoolers and begins as small vesicles progressing to pustules that extend radially with satellite lesions. Vesiculopustular lesions rupture, exposing a red, moist base and purulent discharge, which forms thick, yellow, or honey-colored adherent crusts. Lesions are usually painless, asymptomatic and have little surrounding erythema, and tend to occur on traumatized skin (eg, insect bite, abrasion), commonly in hot, muggy summer months. Exposed body surfaces such as the face, nose, mouth, or extremities are most commonly affected. Pruritus is common and scratching causes lesions to spread through autoinoculation. Regional lymphadenopathy is common, but constitutional symptoms are absent or minimal.
Bullous impetigo is most commonly seen in newborns, infants, and preschoolers. The bacterial reservoir is the upper respiratory tract (eg, nose, conjunctiva) of asymptomatic carriers who spread the pathogen to the child’s skin. Lesions result from exfoliative toxin produced by bacteria at the contact site and begin as vesicles that progress to flaccid bullae with little or no surrounding erythema and clear to cloudy contents. Rupture leaves a narrow rim of scale at the edge of shallow, moist, red erosions (scalded skin appearance). Nikolsky sign is absent (unlike staphylococcal scalded skin syndrome). Lesions may be few and localized (usually covered areas) or numerous and widely scattered. Common sites are trunk, perineum, buttocks, and extremities. Lesions heal without scarring. There is no seasonal predilection.
Complications include acute poststreptococcal glomerulonephritis (impetigo by GABHS) and rarely serious secondary infections (eg, osteomyelitis, septic arthritis). Differential diagnosis of nonbullous impetigo includes ecthyma, herpes simplex virus infection, varicella, tinea corporis, and localized acute pustular psoriasis. In contrast, differential diagnosis of bullous impetigo includes bullous arthropod bites, poison ivy, child abuse (abusive burn injury), autoimmune blistering disease (eg, linear IgA dermatosis, pemphigus), and epidermolysis bullosa.
Figure 3.8 ▪ Bullous Impetigo.
(A) An intact bullous lesion filled with pus is seen in a 10-day-old neonate. He also had several round, ruptured erosions with a moist, red surface that were surrounded by a narrow ring of scale. Intact or ruptured bullae are round or oval in shape. (Photo contributor: Binita R. Shah, MD.) (B) An infant with numerous flaccid bullae filled with pus. (Reproduced with permission from: Shah BR and Laude TL: Atlas of Pediatric Clinical Diagnosis. WB Saunders, Philadelphia, 2000, p. 93.)
Diagnosis is clinical, though the aspirate from the lesion may be cultured and Gram stain smear obtained. Though usually self-limited, untreated infection may last for weeks or months. Advise patients and caregivers to wash the affected area with antibacterial soap once or twice a day, and remove crusts, which can be softened by soaking area with a wet cloth compress, before applying topical therapy. Prescribe topical mupirocin ointment for localized impetigo (bullous or nonbullous) to eradicate the infection and prevent person-to-person spread. For generalized impetigo, or if there is involvement of multiple family members, prescribe systemic antibiotics covering mixed pathogens (GABHS and S aureus). Depending on the prevalence of methicillin-resistant or methicillin-sensitive S aureus in the community, consider oral penicillinase-resistant β-lactam drugs (eg, dicloxacillin), a first- or second-generation cephalosporin, clindamycin or doxycycline (children >8 years of age), or trimethoprim-sulfamethoxazole (for bullous impetigo). Refer patients with recurrence for evaluation and treatment of nasal carriage of S aureus.
Figure 3.9 ▪ Bullous Impetigo.
A 7-month-old infant was referred to the emergency department with this lesion that was thought to be an inflicted burn injury (child abuse). Aspiration of the lesion showed gram-positive cocci in clusters on Gram stain and culture was positive for Staphylococcus aureus. Posttraumatic paronychia due to S aureus should also be considered in the differential diagnosis. (Photo contributor: Binita R. Shah, MD.)
A pathognomonic finding of bullous impetigo is a ring of scale at the periphery of an eroded lesion with a varnished surface.
Impetigo is a highly contagious infection and spread is facilitated by poor hygiene.
Staphylococci can be isolated from bullous impetigo lesions even though culture of staphylococcal scalded skin syndrome lesions is negative.
Ecthyma is a skin infection caused by group A β-hemolytic streptococci (GABHS or S pyogenes) and/or S aureus. Unlike impetigo, which is superficial, ecthyma involves deeper layers of the skin (the entire thickness of the epidermis to the upper reaches of the dermis). Ecthyma is seen in children of all ages and more frequently during summer. Predisposing factors include preceding minor skin trauma (eg, abrasions, insect bites), conditions associated with pruritus (eg, scabies, pediculosis), poor hygiene, and malnutrition. Lesions begin as vesicles or vesiculopustules with an erythematous base and rupture to form crusts and erode through the epidermis into the dermis, forming indolent “punched-out” ulcers with elevated margins. Ulcers become elevated and obscured by thick, dark greenish-yellow tightly adherent crusts that contribute to the persistence of the infection. Lesions are discrete and round and the most common site is lower legs. Lesions spread by autoinoculation and heal with scarring (unlike impetigo). Complications include cellulitis (untreated ecthyma) and poststreptococcal glomerulonephritis. Differential diagnosis includes cigarette burns (due to child abuse) and ecthyma gangrenosum (Pseudomonas aeruginosa infection).
Figure 3.11 ▪ Ecthyma.
An enlarging, slightly painful lesion which started as a “blister” on the forearm (without any prior history of trauma). Culture grew S pyogenes. Ecthyma is a discrete, round lesion with a dark crust in the center surrounded by a rim of shallow ulceration. (Photo contributor: Andrea Marmor, MD.)
Diagnosis is clinical. Culture of the exudate (beneath an unroofed crust) reveals GABHS and S aureus. Advise washing the affected area with antibacterial soap and removal of the crust (facilitated by softening the crust by soaking with a wet cloth compress). Prescribe topical mupirocin therapy until all lesions have cleared. Depending on the prevalence of methicillin-resistant or methicillin-sensitive S aureus in the community, antibiotic options include oral penicillinase-resistant β-lactam drugs (eg, dicloxacillin) or a first- or second-generation cephalosporin, clindamycin or doxycycline (children >8 years of age).
Thick crusts and underlying ulcers differentiate ecthyma from non bullous impetigo.
Ecthyma can be mistakenly attributed to cigarette burns of child abuse.
Figure 3.13 ▪ Ecthyma versus Cigarette Burn.
Ecthyma (A) may be confused with cigarette burns (B). Ecthyma lesions are frequently of different sizes and are associated with crusting. Cigarette burns are circular punched-out lesions of uniform size with an average diameter of about 8 to 10 mm and have a smooth well defined edge. (Photo contributor: Binita R. Shah, MD [A]; Photo B. Reproduced with permission from: American Academy of Pediatrics: The Visual Diagnosis of Child Physical Diagnosis. The C. Henry Kempe National Center on Child Abuse and Neglect. Elk Grove Village, IL, American Academy of Pediatrics, 1994, p. 25.)
Erysipelas is a distinct skin infection involving the uppermost layers of the subcutaneous tissue and cutaneous lymphatic vessels. It is caused by group A β-hemolytic streptococci (GABHS) in the majority and rarely by groups G, C, and B streptococci and occurs most frequently in infants, young children, older adults, and debilitated patients. The organism gains access to the deeper layers of the skin through breaks (eg, abrasions, lacerations, wounds, chronic ulcers). Predisposing factors include lymphedema, local lymphatic dysfunction, venous stasis, diabetes mellitus, malnutrition, and immunocompromised states. Onset is usually abrupt with constitutional symptoms (eg, fever, chills, malaise). Common sites are extremities (usually associated with a wound) and face (usually associated with pharyngitis). Initiating lesion is frequently inconspicuous and spreads peripherally with a raised, advancing border. The lesion is fiery red or salmon colored, hot, tender, tense, and indurated well-circumscribed plaque (sometimes with peau d’orange appearance) with a sharp demarcated border distinguishing it from the surrounding normal tissue. Reddish lymphatic streaks projecting from the margins of the lesion toward regional nodes may be noted. Intense edema may lead to formation of vesicles or tense bullae that later rupture and crust (bullous erysipelas). A “butterfly” appearance with involvement of both cheeks and nasal bridge may occur with involvement of the face. Regional lymphadenopathy may be present. Desquamation of involved skin may occur 5 to 10 days into the illness. Complications are same as with any GABHS infection. Erysipelas produces lymphatic obstruction leading to impaired lymphatic drainage causing lymphedema, which predisposes to recurrent episodes of erysipelas frequently at the same site and permanent local swelling. Differential diagnosis includes cellulitis, erysipelas-like presentation due to other bacterial infection (eg, S pneumoniae, S aureus), necrotizing fasciitis, and contact dermatitis.
Figure 3.14 ▪ Erysipelas.
A rapidly spreading tender facial rash and high fever were complaints of this girl. She had scratch marks on her cheek (portal of entry). The sharp demarcation between the salmon-red erythema and the normal surrounding skin is evident. Marking the margins of the erythema with ink (as seen in the photo) helps in following the clinical course (progression or regression) of the infection. (Photo contributor: Binita R. Shah, MD.)
Figure 3.15 ▪ Butterfly Rash of Erysipelas.
A rapidly spreading (<12-hour duration), tender, erythematous, indurated facial rash was seen in this girl with very high fever and leukocytosis. The sharp demarcation between erythema and the normal surrounding skin is evident. Erysipelas may create a “butterfly” appearance (mimicking the rash of systemic lupus erythematosus) on the face. She gave a history of falling off the monkey bar 2 days prior to appearance of this rash. Within 6 months after this infection, she presented again with a second episode of erysipelas at the same site. (Reproduced with permission from: Shah BR, Santucci K, Tunnessen W: Erysipelas. Arch Pediatr Adolesc Med 1995;149:55.)
Diagnosis is clinical. Hospitalize patients with infection involving the face with systemic signs for intravenous antibiotics (eg, ceftriaxone) for at least 48 to 72 hours. Consider complete blood count (leukocytosis with a left shift), a blood culture, and/or a culture by aspiration from the advancing margin of the lesion. If cellulitis due to S aureus cannot be excluded by examination, depending on the prevalence of methicillin-resistant or methicillin-sensitive S aureus in the community, antibiotic options include penicillinase-resistant β-lactam drugs (eg, oxacillin) or clindamycin. Prescribe oral antibiotics for patients with milder presentations with a close follow-up. Advise rest, immobilization, elevation of the affected part, and cool, wet dressings as supportive therapy. Extension into deeper soft tissues is rare and surgical débridement is not necessary.
Figure 3.17 ▪ Cellulitis; Differential Diagnosis of Erysipelas.
Cellulitis spreads more slowly and extends more deeply into the subcutaneous tissues; hence, the borders of cellulitis are ill-defined (in contrast to erysipelas). Group A β-hemolytic Streptococcus and Staphylococcus aureus are common pathogens causing cellulitis. Streptococcus pneumoniae and Haemophilus influenzae can cause buccal cellulites associated with bacteremia in unimmunized young children. (Photo contributor: Binita R. Shah, MD.)
Necrotizing fasciitis (NF; also known as streptococcal gangrene, flesh-eating bacteria syndrome, hospital gangrene, or necrotizing erysipelas or necrotizing cellulites) is a life-threatening bacterial infection of the fascia and subcutaneous tissues. Patients present with an erythematous, indurated, tender, ill-defined plaque (often mistaken for cellulitis) that manifests disproportionate pain and tenderness. The lesion is dusky purple with vesicles/bullae sometimes filled with maroon or violaceous fluid. Subcutaneous emphysema or crepitus (some cases) may be present and there may be loss of feeling on the skin. The lesion expands rapidly with undermining of overlying skin (important clue for diagnosis), progressing to necrosis and gangrene. Signs of toxicity include (high fever, malaise, altered sensorium, shock). Fournier’s gangrene is NF of perineum, scrotum, and penis. Predisposing factors include infections (eg, varicella), contaminated surgical wounds, IV drug or alcohol abuse, and immunocompromised states. Bacterial myonecrosis refers to involvement of the muscle. Various etiologies include S pyogenes (most common pathogen), groups B, C, or G streptococci, S aureus, P aeruginosa, anaerobes (eg, Bacteroides, Peptostreptococcus, Clostridium spp) and polymicrobial (gram-negative bacilli [eg, Escherichia coli, Proteus spp] and anaerobic bacteria). The majority of cases occur as extensions from localized nearby skin infections that expand along fascial planes, leading to edema, vascular injury, and thrombosis resulting in widespread necrosis of the superficial fascia, adjoining tissues, and deeper layer of dermis. Associated compression or destruction of nerves innervating skin results in anesthesia. Differential diagnosis includes erysipelas, cellulitis, and purpura fulminans. Complications include multiorgan failure with oliguria, acute respiratory distress syndrome, disseminated intravascular coagulation, myocardial failure, and fluid and electrolyte disturbances (extravasation of intravascular fluid into tissues).
Figure 3.18 ▪ Necrotizing Fasciitis.
(A) A 9-day-old neonate presented with high fever, moaning, and slightly indurated swelling with bluish discoloration on the back. (B) Within 12 hours, there was vesiculation and purplish discoloration. This photograph was taken 8 hours following the first surgical exploration and débridement and shows the underlying muscle and necrotic borders. (C) Close-up showing necrotic borders and pus over the underlying muscle. Both blood and tissue cultures grew Staphylococcus aureus. (D) Multiple surgical explorations and débridement were performed followed by skin grafting during recovery. (Photo contributor: Binita R. Shah, MD.)
Necrotizing fasciitis is a medical emergency. Consult surgery emergently for surgical exploration, biopsy (frozen-section biopsy allows rapid evaluation of the pathology to confirm the diagnosis and identification of pathogens underlying the intact skin), débridement of all necrotic tissue, and fasciotomy. Consult infectious disease specialist and begin empiric broad-spectrum IV antibiotics (eg, ampicillin-sulbactam or ampicillin with either clindamycin or metronidazole and vancomycin). Obtain CBC, comprehensive metabolic panel, and coagulation profile (leukocytosis with immature cells, anemia, hyponatremia, hypocalcemia, hypoproteinemia, evidence of disseminated intravascular coagulation, and elevated values of blood urea nitrogen, creatinine, and liver enzymes may be noted). Perform fine-needle aspiration from the involved area (may show presence of pus and bacteria on Gram stain), and send aspirated material and blood culture for both aerobic and anaerobic pathogens. Consider radiograph of the affected area (may show presence of subcutaneous gas, which mandates rapid surgical exploration; however, absence of soft tissue gas does not exclude diagnosis). Consider computed tomographic scan, ultrasound, or magnetic resonance imaging for diagnosis in patients with early signs (when diagnosis is unclear); however, these modalities should never delay immediate surgical exploration in patients with obvious signs. Hospitalize all suspected cases of NF to ICU for ongoing management. Repeat débridement within 24 to 48 hours may be necessary because of continued spread of the infection into surrounding tissues. Other treatment modalities may include hyperbaric oxygen.
Sine qua non of NF is fascial necrosis with widespread undermining of the skin. The ability to pass a sterile instrument along a plane superficial to the deep fascia without resistance is indicative of NF.
Presence of an indurated “wooden” plaque adjacent to infected skin coupled with extreme pain in an area of rapidly advancing edema and inflammation are important clues.
Marked systemic toxicity and pain out of proportion to the local findings (in contrast to the usual patient with cellulitis) suggest NF.
Ecthyma gangrenosum is a pathognomonic cutaneous manifestation of Pseudomonas aeruginosa septicemia; other skin lesions include subcutaneous nodules, vesicular lesions, gangrenous cellulitis, and petechiae rash. Ecthyma gangrenosum usually occurs as a result of bloodborne metastatic seeding to the skin from the bacteremia, or rarely as a primary lesion without bacteremia. Predisposing factors for Pseudomonas septicemia include immunosuppression (eg, malignancy, diabetes, malnutrition, cystic fibrosis), debilitated preterm newborns, severe thermal burns, disorders leading to severe neutropenia or pancytopenia, hospitalized patients on intensive antibiotic treatment, or those with indwelling urinary, arterial, or venous catheters. Skin lesions begin as hemorrhagic (purpuric) macular, vesicular, pustular, or bullous lesions and evolve into punched-out necrotic ulcers with raised edges with a rim of erythema. Lesions remain localized or more typically extend over several centimeters ultimately becoming a round, indurated, painless lesion with a characteristic central grey-black eschar. Either a single ulcer or multiple (noncontiguous) ulcers may be seen. Common sites include perineal or gluteal region, extremities, trunk, face, intertriginous areas, and axilla. Lesions take a few weeks to heal. Differential diagnosis includes ecthyma gangrenosum–like lesions in sepsis from other pathogens (eg, Candida spp, S aureus, S pyogenes), thermal burns, pyoderma gangrenosum, purpura fulminans, and brown recluse spider bite.
Figure 3.20 ▪ Ecthyma Gangrenosum.
(A) Purpuric macular lesions involving the perineum, buttocks, and trunk in a malnourished infant (fed only diluted soy formula) presenting in septic shock. (B), (C), and (D) Close-up of lesions showing progression to necrotic ulcers with dense black eschars in the center. Note the surrounding erythematous halo with raised edges. Both blood and wound cultures were positive for Pseudomonas aeruginosa. (A, B, C. Reproduced with permission from: Secord A, Milla C, Shah BR: Picture of the month. Ecthyma gangrenosum. Am J Dis Child 1993;147:795; and Photo D. Reproduced with permission from: Shah BR and Laude TL: Atlas of Pediatric Clinical Diagnosis. WB Saunders, Philadelphia, 2000, p. 99.)
Stabilize patient based on abnormal vital signs (patients with ecthyma gangrenosum are usually septic). Hospitalize to ICU for IV antibiotic therapy and general supportive care including wound care. Begin antibiotic therapy with an aminoglycoside (eg, tobramycin, gentamicin) and an antipseudomonal penicillin (eg, ticarcillin, piperacillin). Obtain CBC (usually neutropenia especially with septicemia), comprehensive metabolic panel, coagulation profile, blood culture and needle aspiration and culture of the lession (Gram’s stain may show presence of bacteria). Consult dermatologist if diagnosis is unclear; a skin biopsy may show numerous bacteria invading the blood vessels (invasion of media and adventitia of vein walls deep in the dermis with very few inflammatory cells).
Toxic shock syndrome (TSS) is a potentially fatal systemic infection by toxin-producing strains of either S aureus (S aureus–mediated TSS) or S pyogenes (S pyogenes–mediated TSS). Diagnosis is made using published criteria. S pyogenes–mediated TSS occurs commonly in young children. Predisposing factors include varicella, HIV infection, diabetes mellitus, IV drug use, and invasive infections (eg, bacteremia, pneumonia, osteomyelitis, endocarditis).
Figure 3.21 ▪ Streptococcal Toxic Shock Syndrome.
(A) An 8-year-old girl presented with fever, hypotension, oliguria, and infected varicella lesions with multiorgan involvement. Note also the bilateral periorbital edema. Her blood culture was positive for S pyogenes. (B) Close-up of her nose showing honey-colored crusted lesions that are characteristic of S pyogenes impetigo. (Photo contributor: Binita R. Shah, MD.)
S aureus–mediated TSS is seen less commonly in children and most cases occur in women of age 15 to 34 years (reflecting association with menses). Nonmenstrual cases occur in people of all ages and in both sexes. Predisposing factors include use of tampons during menstruation, foreign body placements (eg, contraceptive sponge, central lines), primary S aureus infections (eg, cellulitis, endocarditis), postoperative wound infections, skin or mucous membrane disruptions (eg, burns, insect bites) and vaginal or pharyngeal colonization. Onset may be abrupt or preceded by a prodromal illness of fever, chills, and myalgias. Rash (seen almost always in first 24 hours of illness) may be faint and often mistaken for flush associated with fever. Beefy, red hyperemia of mucous membranes, conjunctival injection, strawberry tongue, erythema, and edema of palms and soles (findings similar to Kawasaki disease) are often seen. Pelvic exam is usually normal except for subtle erythema and edema of the skin of the inner thigh and perineum in menstrual TSS. The focus of the staphylococcal infection may be inconspicuous, with absent signs of inflammation in skin or wound lesions in nonmenstrual TSS.
Complications of TSS include acute renal failure, acute respiratory distress syndrome, overwhelming sepsis, DIC, and multiorgan failure leading to death. Differential diagnosis includes Kawasaki disease, scarlet fever, septic shock from other etiology (eg, meningococcemia, Rocky mountain spotted fever, gram-negative sepsis), measles or atypical measles, ehrlichiosis, leptospirosis, and drug hypersensitivity (eg, Stevens-Johnson syndrome, toxic epidermal necrolysis).
Assess and stabilize vital signs, including fluid resuscitation and pressor agents, as indicated for septic shock. It may be impossible to distinguish clinically both forms of TSS; begin empiric antibiotic therapy that includes antistaphylococcal agents (eg, vancomycin and nafcillin) and a protein synthesis–inhibiting agent (eg, clindamycin). Obtain CBC, blood culture, cultures from the site of infection (skin or soft tissues), vaginal culture (for suspected menstrual TSS), serum electrolytes, BUN, creatinine, liver enzymes, and radiologic studies (as indicated). Consult surgery for exploration, biopsy, and resection of necrotic tissue in NF, drainage of the infected sites, or removal of foreign bodies. Hospitalize patients to ICU for further management.
Figure 3.22 ▪ Cellulitis in Streptococcal Toxic Shock Syndrome (TSS).
(A) Cellulitis involving the thigh and lower leg was seen in this child with AIDS. He presented with septic shock and multiorgan failure with a blood culture positive for S pyogenes. (B) Cellulitis of abdominal wall in an adolescent patient presenting with TSS. (Photo contributor: Binita R. Shah, MD.)
Fever, rash, desquamation, hypotension, and multiorgan involvement are the hallmarks of TSS.
TSS can be confused with many other causes of fever with mucocutaneous manifestations.
Do not use clindamycin alone as an initial empiric therapy, as 1% to 2% of S pyogenes organisms in the United States are resistant to clindamycin.
Women with menses-related TSS may experience one or more recurrent episodes. Advise against use of tampons and barrier methods of contraception.
Figure 3.24 ▪ Staphylococcal Toxic Shock Syndrome (TSS).
(A, B) Diffuse erythroderma with innumerable pustular lesions, high fever, vomiting, and diarrhea were the presenting complaints of this patient with TSS. Her blood culture was positive for S aureus. (C) Close-up showing pustular lesions. Culture of these pustules was negative for S aureus. (Photo contributor: Binita R. Shah, MD.)
| Confirmed case | Presence of all laboratory and clinical findings below | |
| Probable case | Positive culture from nonsterile site and all clinical findings below (and no other cause for illness identified) | |
| Laboratory findings | Isolation of Streptococcus pyogenes | |
| From a normally sterile site (eg, blood, cerebrospinal fluid, peritoneal fluid, tissue biopsy specimen) | ||
| From a nonsterile site (eg, throat, sputum, vagina, surgical wound, or superficial skin lesion) | ||
| Clinical findings | ||
| Hypotension | Systolic blood pressure ≤90 mm Hg in adults or <5th percentile for age in children | |
| Multisystem involvement (at least two of following) | Renal | Creatinine ≥2 mg/dL for adults or two times or more the upper limit of normal for age |
| Coagulopathy | Platelets ≤100,000/mm3 or disseminated intravascular coagulation | |
| Hepatic | Serum alanine and aspartate aminotransferases or total bilirubin values 2 times or more the upper limit of normal for age | |
| Pulmonary | Acute respiratory distress syndrome | |
| Skin | Erythematous macular rash that may desquamate | |
| Soft tissue | Necrosis, including necrotizing fasciitis or myositis, or gangrene | |
| Probable case | Meets laboratory criteria below and has 4–5 of the clinical findings listed below | |
| Confirmed case | Meets laboratory criteria and all 5 clinical findings below, including desquamation, unless the patient dies before desquamation occurs. | |
| Laboratory criteria | Negative results on following tests (if obtained) | |
| Blood, throat, or cerebrospinal fluid cultures (blood culture may be positive for Staphylococcus aureus) | ||
| Serologic tests for Rocky Mountain spotted fever, leptospirosis, or measles | ||
| Clinical findings | ||
| Fever | 38.9°C (102.0°F) or greater | |
| Rash | Diffuse macular erythroderma (nonpruritic) | |
| Desquamation | 1 to 2 weeks after onset (particularly palms, soles, fingers, toes) | |
| Hypotension | Systolic BP ≤90 mm Hg for adults | |
| <5th percentile for age for children <16 years of age | ||
| Orthostatic drop in diastolic BP ≥15 mm Hg from lying to sitting | ||
| Orthostatic syncope or orthostatic dizziness | ||
| Multisystem involvement (three or more of the following) | Gastrointestinal | Vomiting or diarrhea at onset of illness |
| Muscular | Severe myalgia or creatinine phosphokinase >2 times the upper limit of normal | |
| Mucous membrane | Vaginal, oropharyngeal, or conjunctival hyperemia | |
| Renal | Blood urea nitrogen or serum creatinine level >2 times upper limit of normal or urinary sediment with ≥5 white blood cells per high-power field in absence of urinary tract infection | |
| Hepatic | Total bilirubin, aspartate, or alanine aminotransferase level >2 times the upper limit of normal | |
| Hematologic | Platelet count ≤100,000/mm3 | |
| Central nervous system–related | Disorientation or alterations in consciousness without focal neurologic signs when fever and hypotension are absent | |
Staphylococcal scalded skin syndrome (SSSS), also known as Ritter disease (SSSS of the newborn) and Lyell disease, is a toxin-mediated disease caused by Staphylococcus aureus that produces exfoliative toxins (ETA and ETB). S aureus colonizes mucous membranes of the nasopharynx, eyes, and other areas (eg, umbilical stump, circumcision site), producing a localized infection. Toxin produced in these areas circulates and acts specifically at the zona granulosa of the epidermis, leading to characteristic exfoliation. SSSS is most commonly seen in infants and young children (90% of cases <6 years; 62% <2 years of age). Infection in older children and adults is related to a decreased renal clearance of the toxin (eg, patients with renal insufficiency) or immunosuppression (eg, HIV infection).
Figure 3.25 ▪ Staphylococcal Scalded Skin Syndrome (SSSS).
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