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Psoriasis is a common disease, the pathophysiology of which relates to immune activation. Patients with psoriasis have been hypothesized to be at greater risk for lymphoproliferative malignancies, related not only to broad immune activation but also to treatment with immunosuppressive medications. In this cohort study, Gelfand et al compare the rate of lymphoma in patients with psoriasis with that in patients with no history of psoriasis and find that patients 65 years or older with psoriasis develop lymphomas at 3 times the rate of patients without psoriasis. Psoriasis may be added to the list of chronic inflammatory diseases linked to the development of lymphoproliferative malignancies. Whether this increased risk is related to the severity of the disease or to systemic therapies remains a topic for further study.
Azelaic acid (AzA) is a naturally occurring dicarboxylic acid used topically in the treatment of mild to moderate acne vulgaris. In this multicenter, double-blind, randomized, parallel-control group study, Elewski et al compare the efficacy and safety of 15% AzA gel with 0.75% metronidazole gel in 251 patients with papulopustular rosacea. Twice-daily AzA treatment was found to be consistently superior to metronidazole gel with respect to the overall assessment of improvement by both investigators and patients in the reduction of lesions and erythema. While the effectiveness of metronidazole gel plateaued after week 8, AzA gel continued to show progressive improvement over 15 weeks.
Numerous observations support the hypothesis that activated T cells play an essential role in the pathogenesis of psoriasis, and knowledge of this role has allowed for the development of selective therapeutic modalities that are potentially more effective and less toxic than the systemic therapies more commonly in use. In this double-blind, randomized, placebo-controlled trial, Skov et al evaluate the efficacy of subcutaneously administered HuMax-CD4, a fully human anti-CD4 monoclonal antibody, in the treatment of moderate to severe psoriasis. HuMax-CD4 was found to be quite safe, and a moderate therapeutic effect was observed after just 4 weeks of treatment, which suggests that longer treatment would lead to an even more substantial reduction in Psoriasis Area Severity Index scores.
Venous malformations are localized or diffuse errors of embryonic development that range in clinical presentation from varicosities and ectasias through localized masses to more complex lesions that can permeate any organ system. The treatment of extensive venous malformations is complicated by the fact that surgical options may lead to a loss of motor function, nerve damage, and massive bleeding. Although no uniformly safe sclerosant has been identified, sclerotherapy has been used as an alternative or complementary treatment to surgical therapy. In this retrospective study, Cabrera et al demonstrate that percutaneous sclerotherapy by direct injection of polidocanol microfoam under duplex ultrasound guidance is simple and innocuous and represents the treatment of choice in the management of congenital venous malformations.
A 42-year-old man with a venous malformation of the hand, before the start of treatment (A) and at 9 months after 12 sessions of polidocanol microfoam sclerotherapy (B).
The neurophysiologic basis for itching has been recently clarified: the neuronal system for pruritus includes primary afferent neurons activated by histamine as well as spinothalamic projection neurons. This model fails to completely explain, however, the clinical patterns of pruritus seen in patients with atopic dermatitis. In this comparative study, Ikoma et al perform histamine prick testing in lesional and nonlesional skin of patients and controls, and their results suggest that facilitated spinal processing (a "lowered itch threshold") plays a more important role in the itch associated with atopic dermatitis than histamine sensitization.
This Month in Archives of Dermatology. Arch Dermatol. 2003;139(11):1396. doi:10.1001/archderm.139.11.1396