Injection drug use (IDU) accounts for 12% of all illicit drug use in the United States. Intravenous routes are often preferred because of the rapid drug response. Intravenous injecting typically begins in the veins of the arms and upper body, but as these sites become more difficult to find, the veins of the groin, leg, and feet are used. Complications of IDU include venous scarring and collapse, abscess formation, nerve and muscle damage, and lymphatic blockage. In addition, IDU augments or intensifies the typical chronic venous disease (CVD) risk factors affecting the general population. In this review, Pieper et al point out the importance of obtaining a substance-abuse history when evaluating for risk of CVD.
Venous insufficiency causes 70% of all leg ulcers. Physical activity and adequate compression therapy are essential noninvasive treatments for venous leg ulcers. Leg exercises (particularly walking) stimulate the calf muscle pump, supporting venous circulation. Compression therapy improves calf muscle pump effectiveness, reduces venous volume, lowers venous pressure, and improves the microcirculation, thus preventing edema and reducing the development of venous skin changes. In this descriptive cross-sectional study, Heinen et al demonstrate that moderate strenuous activity levels in patients with venous leg ulcers are quite low and that less than half of patients report full compliance with compression therapy. Strict compliance with these noninvasive treatments provide demonstrable benefit with respect to wound healing, suggesting that patients should be more fully educated and urged to follow these recommendations.
It has been more than 25 years since β-adrenergic receptors were first noted to be expressed in the skin, but their functional importance remains unclear. β-Adrenergic receptors may play a role in cutaneous wound repair. Receptor agonists decrease the rate of keratinocyte migration in vitro and impede wound healing in vivo. Receptor antagonists increase cultured keratinocyte migratory speed and improve wound epithelialization in vivo. In this retrospective cohort study, Margolis et al demonstrate a strong protective association between β-adrenergic receptor agonists and venous leg ulcers. These epidemiologic data are supported by strong laboratory evidence, suggesting the need for a randomized clinical trial of these agents.
Staphylococcus aureus is a major cause of local skin infections. Virulence factors include over 40 secreted proteins, enzymes, and toxins that establish and maintain infections, sometimes through an effect on the local immune response. In this study, Mertz et al demonstrate a direct association between the number of white blood cells (WBCs) in a local skin infection and the toxin genes that S aureus carries. Although the physical appearance did not differ, lesions with the fewest WBCs were more likely to be infected with S aureus strains capable of producing exfoliative toxins A and B, while the lesions with the most WBCs were more likely to be infected with a Panton-Valentine leukocidin–producing organism. These data suggest that the local immune response may not always offer an accurate estimate of the seriousness of an infection.
Hydroxyurea is a chemotherapeutic agent that inhibits DNA synthesis and promotes cell death in the S phase of the cell cycle. Hydroxyurea is generally well tolerated and has a low toxicity profile, but painful leg ulcers may rarely complicate long-term, high-dose use for myeloproliferative disease. In this case series, Romanelli et al describe a pronounced association between hydroxyurea therapy and the development of painful leg ulcers unresponsive to standard therapy. These patients were successfully treated with local Promogran dressing therapy (Johnson & Johnson Wound Management, Piscataway, New Jersey) every other day and then twice weekly. Promogran is a freeze-dried sponge containing oxidized regenerated cellulose and bovine purified collagen that may inhibit the degradation of growth factors and tissue destruction, thus limiting the damage to collagen synthesis due to hydroxyurea.
This Month in Archives of Dermatology. Arch Dermatol. 2007;143(10):1244. doi:10.1001/archderm.143.10.1244