Leukocyte Adhesion Defect Type 1 Presenting with Recurrent Pyoderma Gangrenosum

Leukocyte adhesion deficiency 1 (LAD-1) is a rare autosomal recessive disorder of leukocyte function. LAD-1 affects about 1 per 10 million individuals and is characterized by recurrent bacterial and fungal infections and depressed inflammatory responses despite striking blood neutrophilia. Patients with the severe clinical form of LAD-1 express <0.3% of the normal amount of the β(2)-integrin molecules, whereas patients with the moderate phenotype may express 2-7%. Skin infection may progress to large chronic ulcers with polymicrobial infection, including anaerobic organisms. The ulcers heal slowly, require months of antibiotic treatment, and often require plastic surgical grafting. The diagnosis of LAD-1 is established most readily by flow cytometric measurements of surface CD11b in stimulated and unstimulated neutrophils using monoclonal antibodies directed against CD11b. Pyoderma gangrenosum (PG) is an uncommon condition characterized by recurrent sterile, inflammatory skin ulcers. Commonly, PG occurs in the context of inflammatory bowel disease or rheumatic, hematologic, or immunologic disorders. Here, we present a 5-year-old female with a long history of PG, which healed with atrophic scarring, who was ultimately diagnosed with leukocyte adhesion deficiency type 1 (LAD1). She had a good response to high-dose prednisone therapy (2 mg/kg) and was discharged after 3 weeks of admission but only to be re-admitted 3 weeks later with severe pneumonia. During hospital stay, she developed pneumothorax and pneumomediastinum and later succumbed to her illness.