Diffuse cutaneous leishmaniasis of the new world B55.1

Diffuse (disseminated) cutaneous leishmaniasis is a special form of cutaneous leishmaniasis that can occur in cases of selective anergy to leishmania, infection with L. aethiopica, L. amazonensis, L. braziliensis, L. mexicana and L. guyanensis.

In northern Brazil/Peru, this form develops in around 0.2% of those infected.

In Ethiopia and Sudan, it is found in around 20% of infected people.

In Europe, such variants can occur sporadically.

Due to a suppressed cell-mediated immune response, the pathogens spread hematogenously or lymphogenously throughout the body in an uncontrolled manner. Multiple, non-ulcerating inflammatory papules, nodules and plaques develop. The face can also be affected. This results in nodules, including centrally ulcerated keratoacanthoma-like (Sanchez-Diaz M et al. 2025), leprosy-like confluent plaques (Morrison B et al. 2010), erysipelas-like large plaques and thickening of the eyebrows and earlobes, giving the impression of a facies leontina. Only in diffuse cutaneous leishmaniasis caused by Leishmania aethiopica can the lips and the edges of the nostrils also be affected.

Important: No mucosal lesions occur in the New World variant of the disease.

Clinic, histology: an extremely large number of pathogens are detectable in the lesions. The leishmanin skin test is negative (sign of anergy)

S.u. Leishmaniasis; treatment is difficult, relapses are frequent. Amphotericin B proved successful in individual cases (Morrison B et al. 2010)

1. Morrison B et al. (2010) Diffuse (anergic) cutaneous leishmaniasis responding to amphotericin B. Clin Exp Dermatol 35:e116-119.
2. Sanchez-Diaz M et al. (2025) Widespread umbilicated papules and foot ulcer. J Dtsch Dermatol Ges 23:536-539.
3. Silveira FT (2019) What makes mucosal and anergic diffuse cutaneous leishmaniases so clinically and
   immunopathogically different? A review in Brazil. Trans R Soc Trop Med Hyg pii: trz037. doi: 10.1093/trstmh/trz037.