Treating A Patient With Annular Lesions On The Lower Extremities
A 26-year-old male presented with salmon colored annular lesions extending from the dorsum of his feet proximal into his lower extremities bilaterally. He originally thought he had eczema. The patient had no pertinent past medical history or allergies, and no current medications. The patient had not traveled recently and had no recent history of infection. The lesions were mildly pruritic and he had not changed any of his detergents, soaps or anything else in his environment. He did not relate this rash as appearing after any excessive sun exposure recently. He denied fever, chills and joint pain. The exam revealed reddish, pink-colored annular plaques that varied in size and began at the dorsum of the foot and continuing up the leg below the knee. The lesions did not blanch upon pressure. The lesions were not scaly. No lesions were present on the trunk or the back. There were no vesicles, target lesions or ulcers. Toenails and fingernails showed no signs of dystrophy. His hallux lateral nail border was erythematous and edematous, but this paronychia began months earlier than the current skin rash. There were no scalp lesions. We obtained a biopsy of one of the newest presenting lesions.
Key Questions To Consider
1. What is the most likely diagnosis? 2. What is your differential diagnosis? 3. What are the characteristic lesions in this disease? 4. What is the treatment?
Answering The Key Diagnostic Questions
1. The most likely diagnosis is a form of cutaneous small vessel vasculitis, which is also known as cutaneous leukocytoclastic vasculitis (LCV). 2. Differential diagnoses include: systemic lupus erythematosus, drug reaction, Henoch-Schönlein purpura, purpura from other hemorrhagic causes (thrombocytopenia) and other vessel-based inflammatory conditions such as Sweet’s syndrome and urticarial vasculitis. 3. The characteristic lesion in this disease is classically described as palpable purpura that range in size from a few millimeters to a few centimeters. This lesion does not blanch upon pressure. These lesions usually begin on the lower extremity or on areas of dependency. There might be constitutional signs and symptoms (fever, myalgia, arthralgia) that accompany the local symptoms of pruritus and burning, but generally the skin is solely involved. Urticarial lesions that last greater than 24 hours may also be present. 4. Treatment varies from oral nonsteroidal anti-inflammatory drugs (NSAIDs), systemic steroids and oral antihistamines depending on the severity of the presentation. If one identifies a drug reaction, connective tissue disorder or infection as the basis for this, then consider treatment of the triggering cause or discontinuation of the drug.