Medication Summary
Double-blind studies of the treatment of necrobiosis lipoidica with aspirin and dipyridamole have had varied results but overall have shown some beneficial effects from the therapy. The treatment is based on a theory that necrobiosis lipoidica results from platelet-mediated vascular occlusion or immune mechanisms that alter platelet survival. [28] These drugs are thought to prolong platelet survival time and, hence, prevent further worsening of necrobiosis lipoidica.
Littler and Tschen described the successful use of pentoxifylline to treat a case of necrobiosis lipoidica. [29] Pentoxifylline inhibits platelet aggregation and is believed to decrease blood viscosity by increasing fibrinolysis and red blood cell deformity.
Uncontrolled studies have suggested that ticlopidine, [19] nicotinamide, [20] clofazimine, [21, 22] and perilesional heparin injections [23] can benefit some patients with necrobiosis lipoidica.
Hemorheologic Agents
Class Summary
These agents reduce complications resulting from increased blood viscosity.
Pentoxifylline (Trental)
Pentoxifylline may alter the rheology of red blood cells, consequently reducing blood viscosity. It increases fibrinolysis and red blood cell deformity and also inhibits platelet aggregation.
Antiplatelet Agents
Class Summary
These drugs inhibit platelet aggregation. The drugs are thought to prolong platelet survival time and, hence, prevent further worsening of necrobiosis lipoidica. They also help prevent cerebrovascular accidents and improve renal and systemic function.
Ticlopidine
Ticlopidine is a second-line antiplatelet therapy for patients who fail aspirin therapy.
B Vitamins
Class Summary
These agents may inhibit the synthesis of low-density lipoprotein and very-low-density lipoprotein. This inhibition results in a decrease of total plasma cholesterol. Nicotinamide, and not niacin or other niacin preparations, is a treatment option. [20] Nicotinamide is the physiologically active form of niacin, vitamin B-3. Unlike niacin, nicotinamide in high doses does not lower lipid levels or cause flushing. However, it does exert significant anti-inflammatory effects.
NADH (Nicotinamide adenine dinucleotide)
Nicotinamide moderates inflammatory reactions by inhibiting leukocytic chemotaxis and leukocytic release of lysosomal enzymes. It has been shown to inhibit lymphocytic transformation, antibody production, and mast cell degranulation.
Immunomodulators
Class Summary
Immunomodulators inhibit key factors responsible for the inflammatory response to tissue insult.
Clofazimine (Lamprene)
Clofazimine is known to have anti-inflammatory properties in controlling erythema nodosum leprosum reactions, but its mechanism of action is unknown.
Anticoagulants, Hematologic
Class Summary
Anticoagulants inhibit the formation of blood clots resulting from blood disorders.
Heparin
Heparin augments the activity of antithrombin III and prevents the conversion of fibrinogen to fibrin. It does not actively lyse, but it can inhibit further thrombogenesis. Heparin prevents the reaccumulation of clots after spontaneous fibrinolysis.
Retinoid-like Agents, Topical
Class Summary
Retinoids regulate cell growth and differentiation.
Tretinoin topical (Avita, Retin-A, Tretin-X, Atralin)
Tretinoin inhibits microcomedo formation and eliminates existing lesions. It makes keratinocytes in sebaceous follicles less adherent and easier to remove. The drug is available as a 0.025%, 0.05%, or 0.1% cream and as a 0.01% or 0.025% gel.
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Typical presentation of necrobiosis lipoidica on the lower pretibial legs.
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Red-brown plaque with yellow atrophic center on lower leg.
