Alopecia areata (AA) is a common cause of nonscarring alopecia, and a peribulbar lymphocytic infiltrate is often considered the essential histologic feature. The absence of this finding in many scalp biopsy specimens suggests the need for other diagnostic criteria. Whiting performed 4-mm punch biopsies on the scalp in 50 consecutive patients with AA and sectioned the specimens horizontally. The histopathologic findings were found to depend on the stage of the AA episode. Only in the acute stage did bulbar lymphocytes surround terminal hair follicles in the classic manner. In the subacute stage, decreased anagen and increased catagen and telogen hairs were observed, while in the chronic stage, decreased terminal and increased miniaturized hairs were found with variable inflammation. These data suggest that AA may be diagnosed confidently, even in the absence of the classic inflammatory infiltrate.
The pivotal role of T cells in the pathogenesis of psoriasis is becoming increasingly well understood, and selective targeting of certain T-cell populations has shown promise in improving the efficacy and tolerability of psoriasis treatments. Alefacept preferentially targets memory T cells because of their high level of expression of CD2, the target antigen for this drug. In this multicenter, randomized, double-blind, placebo-controlled trial, Gordon et al describe a correlation between the clinical efficacy and the duration of the response to intravenous alefacept with the blood levels of circulating memory T cells.
Rickettsialpox is an acute, self-limited febrile illness caused by Rickettsia akari and transmitted by a hematophagous mite that infests the common house mouse. The sparse papulovesicular rash and eschar may be mistaken for signs of potentially more serious diseases such as cutaneous anthrax or varicella. Previously, the laboratory diagnosis of rickettsialpox depended on detection of a rise in IgG antibody titers reactive with R akari in acute and convalescent phase serum samples. In this case series of 18 patients with rickettsialpox, Koss et al demonstrate that immunohistochemical staining using an anti–Rickettsia rickettsii antibody in paraffin-embedded skin biopsy tissue is a useful confirmatory test. Rickettsialpox remains endemic in New York City, and the bioterrorism attacks of October 2001 may have led to increased awareness and detection of this disease.
Treatment recommendations for Merkel cell carcinoma (MCC), a rare and potentially aggressive neuroendocrine tumor of the skin, often include both wide excision and adjuvant radiation therapy. In certain anatomic locations or in the setting of certain comorbidities, wide excision may prove impossible. In this retrospective analysis of 9 patients with stage I MCC treated with radiation therapy alone, Mortier et al demonstrate that inoperable MCC may be treated by exclusive radiotherapy with outcomes similar to those of conventionally recommended therapy.
Nonsteroidal anti-inflammatory drugs (NSAIDs) exacerbate chronic idiopathic urticaria (CIU) by a nonallergic mechanism involving cyclooxygenase inhibition. In this prospective, double-blind, placebo-controlled crossover trial, Zembowicz et al demonstrate that the severity and duration of the aspirin-induced wheals in patients with CIU show positive correlation with urinary leukotriene E4 excretion. Neither rofecoxib nor celecoxib elicited such skin eruptions in any of the aspirin-sensitive patients. The fact that cyclooxygenase 2 inhibitors do not induce urticaria in patients with CIU supports the concept that NSAID sensitivity in this disease is associated with overproduction of cysteinyl leukotrienes and most likely depends on inhibition of cyclooxygenase 1.
This Month in Archives of Dermatology. Arch Dermatol. 2003;139(12):1533. doi:10.1001/archderm.139.12.1533