Dermatology

Dermatology
Abdullah Al-Anazi
Elena Pope
Introduction
Rashes presenting to the emergency department may be classified as follows:
  • Morbilliform eruptions (maculopapular)
  • Vesiculobullous eruptions
  • Pruritic eruptions
  • Life-threatening rashes
  • Fungal infections
  • Petechiae and purpura
Morbilliform Eruptions (Maculopapular Rashes)
Differential Diagnosis
  • Viral: measles, rubella, roseola, erythema infectiosum
  • Drug eruptions (usually antibiotics, anticonvulsants)
  • Bacterial: scarlet fever
  • Kawasaki disease
  • Rocky Mountain Spotted Fever
Roseola Infantum
  • Caused by human herpesvirus 6
  • Common age 6 months to 2 years
  • Well-looking child despite high fever
  • Fever persists for 3-4 days
  • Macular or maculopapular rash appears on 3rd-4th day of illness as fever subsides
  • May be associated with febrile seizures (25% of cases)
  • See Figure 51.1 in color insert
Erythema Infectiosum (Fifth Disease)
  • Caused by parvovirus B19
  • Common in spring months and school-age children
  • Incubation period 6-14 days
  • Rash starts on the cheek giving a “slapped cheek” appearance
  • Maculopapular rash develops after 24 hours over trunk and extremities
  • Rash clears with a lacy pattern
  • Complications: transient arthritis, aplastic anemia in children with high bone marrow turnover (sickle cell disease, thalassemia, G6PD deficiency, spherocytosis)
  • Pregnancy risk:
    • 50% of women are seropositive before pregnancy
    • Likelihood of transmission if exposed: 30-50%
    • 2-10% rate of fetal loss
Measles (Rubeola)
  • Caused by measles virus (paramyxovirus)
  • Highly contagious (transmitted by nasal and oral droplets)
  • Incubation period: 1-2 weeks
  • Contagious 3 days before until 4 days after appearance of rash
  • Prodrome: cough, coryza, conjunctivitis, fever, photophobia
  • Clinical presentation:
    • Koplik spots (white papules on buccal mucosa) present 2 days before until 2 days after rash appears
    • Morbilliform rash appears behind the ears spreading toward face, trunk, and then extremities
    • Rash fades after 3-7 days; fine desquamation is common with the exception of palms and soles
    • Complications: otitis media, pneumonia, encephalitis, subacute sclerosing panencephalitis
    • See Figure 51.2 in color insert
Rubella
  • Generalized maculopapular rash with cervical, postauricular, and occipital lymphadenopathy
  • 3-5 days of viral prodrome followed by a pink rash that spreads caudally from head to toes in 24 hours
  • Palatal petechiae may be present
  • Arthritis 1-2 weeks after the eruption (girls more commonly affected)
  • See Figure 51.3 in color insert
Scarlet Fever
  • Exotoxin-mediated rash secondary to group A β hemolytic Streptococcus infection of the pharynx, skin, or perianal area
  • Generalized pinpoint papular eruption (sandpaper rash)
  • Prominent in skin folds: Pastia’s lines
  • Strawberry tongue with circumoral pallor
  • Resolves with desquamation
  • Treatment: oral penicillin
  • See Figure 51.4 in color insert
Rocky Mountain Spotted Fever
  • Caused by Rickettsia rickettsii
  • Incubation period: 2-10 days
  • Clinical features:
    • Fever, headache, myalgias
    • Maculopapular rash erupts on day 3 of illness, may progress to hemorrhagic rash within 24-48 hours
  • Treatment: doxycycline or chloramphenicol
Vesicullobullous Eruptions
Chickenpox
Tags:
Jun 22, 2016 | Posted by in EMERGENCY MEDICINE | Comments Off on Dermatology

Full access? Get Clinical Tree
Get Clinical Tree app for offline access