LAUSR

A previously healthy 1-year-old girl presented with fever and two skin lesions on her right arm. Five days prior to admission, she had fever and small papules that developed into a necrotic ulcer on her right shoulder the next day. Two days prior to admission, a similar ulcer developed on the right upper arm. There was no family history of immunodeficiency or hematological disease. Physical examination revealed two necrotic ulcers on the right arm that were 2 cm and 1 cm in size, with a black eschar and erythematous rim (Fig. 1a). There were no skin lesions in the anogenital or axillary areas. Laboratory tests showed a leukocyte count of 6500/μL and absolute neutrophil count (ANC) of 65/μL. The results of immunological screening, including serum levels of immunoglobulins and complement (C3 and C4), and lymphocyte subsets were unremarkable. Wound culture yielded Pseudomonas aeruginosa, and the condition was diagnosed as ecthyma gangrenosum (EG). Blood cultures were negative. Pathology of the ulcer showed a broadly ulcerated zone of necrotic dermis and subcutis with neutrophilic infiltration. ANC values were 65–1688/μL during hospitalization. Bone marrow aspirate exhibited hypercellularity with myeloid hyperplasia without excess of blasts; however, there was a decrease in segmented neutrophils. Neutrophil-specific antibody was not detected. There were no mutations in ELANE, HAX-1, WAS, CSF3R, or VPS45.L4. Intravenous infusion of cefepime was initiated on the first day of hospitalization, and debridement was performed on the first and third days of hospitalization. After these treatments, the patient’s condition became stable and the necrotic area decreased (Fig. 1b, c). Intravenous antibiotic therapy was continued for 3 weeks. She still demonstrated chronic neutropenia (ANC 173–640/μL) 1 year later, but without serious infections. These observations indicated that she had chronic benign neutropenia. EG is characterized by often fatal cutaneous infections caused by Gram-negative organisms, usually P. aeruginosa. EG commonly occurs in immunocompromised patients, for example, those with neutropenia, leukemia, and multiple myeloma [1]. The presence of bacteremia and neutropenia, as well as delay of appropriate therapy, are often the determinants of clinical outcome [2]. Intravenous anti-pseudomonal agents should be administered and immunological examinations performed on the skin lesions, which are typically ulcers in EG. * Hiro Nakao [email protected]