The spectrum of pigmented purpuric dermatosis and mycosis fungoides: atypical T-cell dyscrasia.

We report the case of a healthy 17-year-old adolescent boy with an unremarkable medical history who presented with an asymptomatic fixed rash on the abdomen, buttocks, and legs. The rash initially developed in a small area on the right leg 2 years prior and had progressed slowly. Prior biopsies were consistent with pigmented purpura. Clinical examination revealed multiple annular purpuric patches on the abdomen, buttocks, and legs covering approximately 20% of the body surface area without lymphadenopathy or hepatosplenomegaly. Additional biopsies demonstrated changes consistent with mycosis fungoides (MF). T-cell receptor g gene rearrangements demonstrated clonality. The patient was diagnosed with stage IB MF of the pigmented purpura-like variant. The patient responded well to psoralen plus UVA therapy. It has been proposed that pigmented purpuric dermatosis (PPD) is a form of cutaneous T-cell lymphoid dyscrasia and that T-cell gene rearrangement studies should be obtained for prognostic evaluation in patients with widespread disease. In our patient, the clinical appearance of the lesions, pathologic findings, and gene rearrangement studies led to the diagnosis of MF. Until the potential for evolution of PPD to malignant disease is better understood, further evaluation of MF in patients with an unusual presentation of pigmented purpura is warranted.

Diagnostic accuracy in patients admitted to hospitals with cellulitis.

Misdiagnosis of non-infectious conditions such as cellulitis is a common error and can result in unnecessary hospitalization and antibiotic use. We sought to prospectively determine the misdiagnosis rate of cellulitis among hospitalized patients and to determine if a visually-based computerized diagnostic decision support system (VCDDSS, also named VisualDx) could generate an improved differential diagnosis (DDx) for misdiagnosed patients. In two separate institutions, attending dermatologists or infectious disease specialists evaluated all consecutive patients hospitalized for "cellulitis" by the emergency department. Among 145 subjects enrolled, misdiagnosis occurred in 41 (28%) patients. The diagnosis most commonly mistaken as cellulitis was stasis dermatitis (37%). At one center, in cases that were misdiagnosed by the emergency department, the VCDDSS included the correct diagnosis in the DDx more frequently than the admitting team (18/28 cases (64%) compared to 4/28 cases (14%), p=0.0003). These results demonstrate the capability of this VCDDSS to assist primary care physicians with generating a more accurate DDx when confronted with patients presenting with possible skin infections. Misdiagnoses may result in a significant source of healthcare costs and misdiagnosis-related patient harm. Inclusion of decision support tools early in the diagnostic workflow may reduce misdiagnosis and result in more efficient healthcare management.

Neonatal eosinophilic pustulosis in a 2-month old.

We describe a 2-month-old preterm neonate presenting with neonatal eosinophilic pustulosis, manifesting as grouped pustules on the cheeks, leukocytosis and marked blood eosinophilia, and histology demonstrating abundant eosinophils without follicular involvement. Complete resolution of his skin lesions occurred spontaneously by 4 months of age, paralleling a decline in his eosinophil count. We discuss the relationship of this eruption to other pustular disorders of infancy and hypothesize a mechanism that may initiate the eruption.