Acute radiation dermatitis commonly occurs following local radiation therapy for various cancers and, when severe, may necessitate disruption of treatment. Intense inflammatory reaction may result in a breakdown of the skin's barrier function and accompanying bacterial colonization. Bacterial superantigens may exacerbate inflammation through activation of T-cells and subsequent cytokine release. We report six cases of severe radiation dermatitis in cancer patients. Four of the six grew pathogenic bacteria, and three had psoriasiform or eczematous reactions at distant sites. Both the radiation dermatitis and the distant cutaneous reactions resolved rapidly on a combination of topical steroids and oral plus topical antibiotic therapy. We suggest that staphylococcal superinfection of acute radiodermatitis intensifies the inflammatory process and hinders repair of the epidermal barrier. Patients with acute radiation dermatitis should be investigated for secondary infection. We emphasize the importance of including topical and oral antibiotic therapy in conjunction with topical corticosteroids to eradicate infection as well as hasten repair of the skin's barrier function. These cases are presented to call attention to the role of Staphylococcus aureus in the pathogenesis of severe radiation dermatitis and the need to include appropriate antibiotic therapy based on culture in the management of acute radiation dermatitis.

The hypereosinophilic syndrome (HES) is defined by a longer than 6-month history of peripheral blood hypereosinophilia (greater than 1.5 x 10(9)/L), with signs and symptoms of internal organ involvement, in the absence of an identifiable cause. HES is therefore a diagnosis of exclusion. Patients have been reported who initially met the criteria for HES but subsequently developed a rare hematologic malignancy known as acute lymphoblastic leukemia with eosinophilia (ALL-Eo). We report such a case in a 10-year-old boy who presented to the pediatric dermatology clinic with unusual, urticarial skin lesions. Although skin involvement is often reported in cases of HES and ALL-Eo, such findings are variable and reports in the dermatology literature are few. We emphasize the importance of continuous monitoring for underlying malignancy in children with urticarial skin lesions in the setting of unexplained hypereosinophilia.

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