Dermatitis Herpetiformis Revealing Acute Lymphoblastic Leukemia in a Child: A Case Report

A two-year-and-nine-month-old girl was referred for widespread bullous and herpetiform skin lesions associated with limb edema and asthenia, evolving over approximately seven months. The initial clinical evaluation raised suspicion of bullous systemic lupus erythematosus based on cutaneous findings and abnormal blood tests, including proteinuria, hypoalbuminemia, and low complement C4. Skin histopathology showed dermal edema with a neutrophilic infiltrate, and direct immunofluorescence revealed granular IgA and C3 deposits along the dermoepidermal junction, findings diagnostic of dermatitis herpetiformis (DH). Serologic tests showed normal total IgA, negative anti-transglutaminase and anti-endomysial antibodies, and positive anti-gliadin antibodies. Jejunal biopsy showed no villous atrophy. The diagnosis of celiac disease was not made, as anti-gliadin antibodies are nonspecific and were not supported by confirmatory serologic or histologic evidence. Hematologic reassessment revealed pancytopenia and circulating blasts, and bone marrow aspiration confirmed acute lymphoblastic leukemia (ALL). The patient was referred to pediatric oncology for treatment of her leukemia. A gluten-free diet was initiated specifically for the management of DH, which is a gluten-sensitive dermatosis. The patient showed a favorable clinical evolution with the resolution of skin lesions. This case highlights an unusual association between DH and pediatric ALL. It underscores the importance of maintaining a broad differential diagnosis that includes hematologic malignancies when evaluating children with atypical or treatment-refractory dermatologic presentations, even when a specific dermatologic diagnosis, such as DH, has been established.