Juvenile ecthyma gangrenosum caused by Pseudomonas aeruginosa revealing an underlying neutropenia: case report and review of the literature.

ABSTRACT

BACKGROUND: Ecthyma gangrenosum (EG) is characterized by the occurrence of erythematous, violaceous or haemorrhagic macules and/or vesicles, often evolving into necrotic ulcers, with a central grey-black eschar. It is a rare skin condition, usually occurring in immunocompromised patients suffering from bacterial sepsis caused by Pseudomonas aeruginosa. However, seemingly healthy children have been diagnosed with this skin disease as well. OBJECTIVES: We report the workup of a case of vulvar EG caused by P. aeruginosa in a toddler, which led to a diagnosis of an underlying neutropenia. Moreover, we provide a brief literature review on those cases of EG where an underlying primary immunodeficiency, neutropenia in particular, was eventually diagnosed. METHODS: A one-and-a-half-year-old girl presented with a history of recurrent (respiratory) infections and the sporadic occurrence of purpuric, vulvar ulcers. Workup consisted of microbiological and haematological investigations, including repeated blood analyses. RESULTS: Bacterial swabs from the vulvar ulcers showed the growth of P. aeruginosa. No concomitant sepsis was present, but laboratory investigations pointed towards a cyclic neutropenia, coinciding with the occurrence of the EG lesions. Topical gentamicin ointment allowed the skin lesions to heal faster. Following the administration of granulocyte colony-stimulating factor (G-CSF), the girl experienced less infections in general and had no recurrence of EG lesions in particular. Treatment with G-CSF could eventually be stopped, and the neutropenia, ultimately transient in nature, completely resolved. CONCLUSION: Children presenting with (anogenital) EG should always alert a physician to consider a potentially underlying immunodeficiency, neutropenia in particular.