12. Dermatology

Dermatologic conditions requiring intensive care are rare, representing 0.47% of all intensive care unit (ICU) admissions.

Mortality is high with a rate of 28.1% in the ICU and 40% overall in-hospital.

Several dermatologic conditions, ranging from mild to life-threatening, should be recognizable and treatable by the ICU physician.

Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis

Epidemiology

Rare, affecting approximately 2/1,000,000 annually

Key Pathophysiology

Severe cutaneous drug reactions predominantly involving the skin and mucous membranes

Stephens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN) are considered to be two ends of a spectrum, differing only by their extent of skin detachment.

Characterized by mucocutaneous tenderness and typically hemorrhagic erosions, erythema, and epidermal detachment from the underlying dermis presenting as blisters and denuded skin

Several drugs are considered “high risk” for inducing SJS/TEN including: allopurinol, trimethoprim–sulfamethoxazole, phenytoin, carbamazepine, quinolones, cephalosporins, nonsteroidal anti-inflammatory drugs, and phenobarbital among others.

Time course from drug administration to symptoms is usually 1 to 4 weeks.

Management and Treatment

Treatment consists of supportive care, including fluid resuscitation and electrolyte management.

Debridement is unnecessary as blistered skin acts as a natural biologic dressing promoting re-epithelialization.

No specific drug therapy has shown efficacy in controlled clinical trials.

Systemic steroids used to be the standard of care but have become increasingly disputed recently.

High-dose intravenous immunoglobulin has shown benefit in non-controlled studies and is occasionally used in children.

Outcomes

High risk of mortality: SJS 1% to 5%, TEN 25% to 35%.

Cellulitis

Key Pathophysiology

Acute, spreading pyogenic inflammation of the dermis and subcutaneous tissue.

Area affected is usually tender, warm, erythematous, and swollen.

Several anatomical and causal variants exist and must be determined to help guide accurate treatment.

The likely bacterial causes include Streptococcus, Staphylococcus aureus and Enterococcus; less often Enterobacteriaceae and Haemophilus influenzae.

Differential Diagnosis

Necrotizing fasciitis, anaerobic myonecrosis, deep venous thrombosis, drug reaction, acute gout, and several other rare pathologies.

Management and Treatment

Initial empirical antibiotic treatment consists of a cephalosporin (cefazolin or ceftriaxone) or vancomycin (if penicillin allergy) for 7 to 14 days.

Broader coverage should be considered for susceptible patients (such as the presence of diabetes or immunocompromise) or in cases with a less common causal agent suspected.