Cutaneous diphtheria is not uncommon in tropical areas, but is very uncommon in temperate regions.
Corynebacterium diphtheriae is only rarely found in the pharynx and nose in tropical areas but is common as a secondary contaminant in skin lesions such as ulcers and abrasions. In temperate areas, lesions may well be traumatic, with C. diphtheriae as a secondary overgrowth.
Lesions are typically ulcers with a steep, undermined edge. The central eschar is tenacious, and is gray to black in color. Lesions may also be less distinctive.
There may be an associated lymphadenopathy.
Systemic manifestations such as neurological changes or myocarditis are rare, except in children.
- Diphtheria antitoxin 20,000-50,000 units IM should be administered if the diagnosis is suspected.
- The organism responds well to penicillin G or erythromycin.