Clinical features:
(1) The patient has a skin infection or wound, which may be painful.
(2) The patient does not have immunity to diphtheria toxin.
(3) The patient shows signs and symptoms of diphtheria.
(4) There is no evidence of pharyngeal involvement.
(5) Culture of the skin lesion yields Corynebacterium diphtheriae with evidence of toxin production.
Skin lesions may include:
(1) an infected wound, including surgical site
(2) an infected insect bite
(3) a chronic skin ulcer (ecthyma diphthericum)
(4) infection of the umbilicus
(5) superinfection of eczema, impetigo or dermatitis
Differential diagnosis:
(1) cutaneous infection with a non-toxigenic strain
(2) pharyngeal diphtheria with a toxigenic strain
