Treating A Patient With Pruritic, ‘Swollen’ Legs
- Volume 26 - Issue 10 - October 2013
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4. Esoterica. In order to satisfy our intellectual need to consider the most remote of diagnostic possibilities, our differential diagnosis list would not be complete without a rare bird. Dermatitis herpetiformis rarely presents on the foot but it is appropriate to consider it in this case because of its characteristic symptoms of intense pruritus and excoriations. Dermatitis herpetiformis is an autoimmune blistering disorder associated with gluten-sensitive enteropathy. It classically affects the extensor elbows, knees, buttocks and back.6 One can diagnose this via cutaneous biopsy and direct immunofluorescence showing deposition of immunoglobulin A in a granular pattern in the upper papillary dermis. Treatment is based on a gluten-free diet and dapsone (Aczone, Allergan).6
Mentally listing these four categories — primary impression, mimicker, worst case and esoterica — and then methodologically ruling each entity in or out will help get us started toward a comprehensive workup, arrival at the best diagnosis and the most effective management.
Key Insights Into Treatment And Prevention
Management of neurodermatitis basically relies on localized topical corticosteroids for inflammation control, central sedation to suppress the itch-scratch cycle and prevention of further scratching.
Topical corticosteroids have three clinically useful mechanisms of action. First, cutaneous vasoconstriction works to reduce erythema and “get the red out.” Secondly, there is the anti-pruritic effect to help break up the itch-scratch cycle. Finally, topical corticosteroids are strong immune system blockers.7
Central nervous system sedation may be necessary to break the itch-scratch cycle. Hydroxyzine (Vistaril, Pfizer) can help to centrally control anxiety and antagonize peripheral H1 receptors. Topical doxepin (Silenor, Somaxon Pharmaceuticals) antagonizes central H1 receptors and inhibits norepinephrine and serotonin reuptake.7 Research has shown gabapentin (Neurontin, Pfizer) and pregabalin (Lyrica, Pfizer) to relieve severe uremic pruritus.8
In the preventative phase of treatment, moisturizers and antipruritics with menthol and N-palmitoyl-ethanolamine help repair the epidermal barrier and act as safe substitutes for scratching.9 Ice can also help block the localized itch sensation.
In the acute phase of treatment, applying an Unna boot from the malleoli to the tibial tubercles helps to reduce stasis, lowers bacterial counts and acts as a barrier to continued scratching. Occluding the lesions is likely to result in better cure rates than the application of topical agents alone.10 After application of antibiotic ointment and triamcinolone (Kenalog, Bristol-Myers Squibb) to each open lesion, loosely apply the zinc oxide paste impregnated elastic gauze directly to the skin akin to a surgical dressing without tension. Then apply a layer of cotton cast padding and finally secure it with an elastic self-adherent wrap.
Patient education can help prevent the repetitive rubbing that initiates and perpetuates this disorder. Those patients with personality traits of excessive pain avoidance, dependency on other people’s desires, and who are more conforming and dutiful are more likely to develop skin disorders.10
Techniques of stress management are often important aspects of neurodermatitis. Discussing the importance of exercise, rest and sleep is helpful. Patients should avoid managing stress with food, caffeine and alcohol. Consultation with a mental health professional can help the patient practice coping measures to reduce stress and pruritus. In patients with diabetes, research has shown that stress management improves HgA1c by 0.5 percent.11
Preparing patients for expected recurrences of acute lesions should be part of the long-term management plan. Patients may interpret recurrent flares as failed treatment from the previous physician. Sequential photographic images are useful to assess progress visually in a disease that is chronic and recurrent in nature.