Diffuse cutaneous leishmaniasis of the new world B55.1

Diffuse cutaneous leishmaniasis is a special form of cutaneous leishmaniasis that occurs when there is selective anergy to Leishmania, infection with L. aethiopica, L. amazonensis, L. braziliensis, L. mexicana, and L. guyanensis. In northern Brazil, this form develops in about 0.2% of infected persons. In Ethiopia and Sudan, it is found in about 20% of infected individuals. In Europe, such variants may occur sporadically.

Due to a suppressed cell-mediated immune response, the pathogens spread uncontrollably throughout the body hematogenously or lymphogenically. Multiple, non-ulcerating inflammatory papules and nodules develop. The face may also be affected. Nodules, leprosy-like confluent plaques (Morrison B et al. 2010), erysipelas-like large plaques, and thickening of the eyebrows and earlobes give the impression of facies leontina. Only in diffuse cutaneous leishmaniasis caused by Leishmania aethiopica can the lips and the edges of the nostrils also be affected. In the New World variant of the disease, mucosal lesions do not occur.

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. Silveira FT (2019) What makes mucosal and anergic diffuse cutaneous leishmaniases so clinically andimmunopathogically
   different? A review in Brazil. Trans R Soc Trop Med Hyg pii: trz037. doi: 10.1093/trstmh/trz037.