ROBIN L.TRAVERSMD, LLM
Pruritus in pregnancy is often neglected and may be related to one of the specific pregnancy-related dermatoses such as intrahepatic cholestasis of pregnancy (ICP). Prompt diagnosis and treatment of ICP is essential to minimize perinatal morbidity or in utero fetal death. In this case series of 13 ICP cases, Ambros-Rudolph et al demonstrate that severe pruritus with or without skin changes in the second half of pregnancy should alert the clinician to the possibility of ICP. Diagnosis may be confirmed by serum bile acid level analysis, even in the setting of normal findings on liver function tests. Skin biopsy is typically unnecessary. Prompt treatment with ursodeoxycholic acid can decrease maternal bile acids, prolong the pregnancy, and minimize fetal risks and maternal symptoms.
Azathioprine is widely used as maintenance treatment of inflammatory bowel disease (IBD). Late adverse reactions to azathioprine include dose-dependent cytopenias that may be anticipated by measurement of thiopurine methyltransferase (TPMT) activity. Early idiosyncratic hypersensitivity reactions related to azathioprine include skin eruptions, although erythema nodosum–like lesions seen in such patients are more likely to be associated with infections or worsening of the underlying IBD. In this case series, de Fonclare et al describe 5 cases of pustular or erythema nodosum–like eruptions associated with high fever due to azathioprine hypersensitivity. Activity of TPMT was not predictive of this adverse effect. Careful analysis of the temporal relationship between azathioprine exposure and the onset of erythema nodosum–like lesions offers important clues to the underlying cause of this condition. If other signs of hypersensitivity are present, discontinuation of treatment with the drug is warranted.
Psoriasis is a chronic inflammatory disorder characterized by elevated levels of tumor necrosis factor (TNF) in serum and affected tissue. Etanercept is a soluble TNF receptor approved for the treatment of moderate to severe plaque psoriasis at a dose of 50 mg twice a week for 3 months followed by a maintenance dose of 50 mg/wk. In this placebo-controlled double-blind trial, Tyring et al demonstrate that extended etanercept therapy at a dose of 50 mg twice a week was safe and effective for many patients. Although antietanercept antibodies were observed, they were all found to be nonneutralizing and had no impact on the efficacy or safety profiles of the drug.
Pemphigus is an autoimmune blistering skin disease. The clinical manifestations of the most common variant, pemphigus vulgaris, are caused by pathogenic antibodies directed against desmogleins 1 and 3. A number of medications have been reported to induce pemphigus variants. Penicillamine is the most common, although other medications, including penicillin, have been rarely implicated. In this analysis of drug purchases from a health maintenance organization central database, Heymann et al demonstrate that penicillin may be associated with the development of pemphigus, although a causal link was not clearly established.
Patient before treatment (left) and after 48 sessions of narrowband UV-B therapy (right).
This Month in Archives of Dermatology. Arch Dermatol. 2007;143(6):696. doi:10.1001/archderm.143.6.696