Answer: Can you identify this condition?

3. Tumid lupus erythematosus

First reported in the literature in 1930, tumid lupus erythematosus (LE) is an uncommon variant of chronic cutaneous LE; it is characterized by multiple smooth, indurated, erythematous to violaceous papules, plaques, or nodules, with no epidermal changes such as scaling or atrophy.^1–5 The lesions are symmetrical and usually appear on sun-exposed regions of the face, upper back, and chest.^1–5 They often resolve without scarring. Histopathology reveals mild to moderate perivascular and periadnexal lymphocytic infiltrate, both superficial and deep, with increased dermal mucin; interface changes at the dermoepidermal junction are usually absent. When performed, immunohistochemical analysis commonly reveals a predominance of CD3- and CD4-positive lymphocytes, with a CD4 to CD8 cell ratio of roughly 3 to 1.⁵ Our patient had similar histopathologic findings.

Patients with tumid LE do not have cutaneous or systemic manifestations of systemic LE or other forms of cutaneous LE; rarely, however, coexistent systemic LE or discoid LE is reported. Serologic findings in tumid LE are mostly unremarkable, although antinuclear autoantibodies, such as anti–double-stranded DNA, anti-Ro/SSA, and anti-La/SSA antibodies, can be present in weak amounts.^1–5 In our patient, antibody titres yielded negative results, while complete blood count, liver function test results, complement levels, and results of urinalysis were all normal.

Differential diagnosis

Clinical differential diagnosis of tumid LE includes pityriasis rosea, guttate psoriasis, and sarcoidosis.^6–8 Pityriasis rosea is a self-limiting, pruritic, papulosquamous eruption that usually involves the trunk and proximal extremities of adolescents and young adults. Clinically, it is characterized by erythematous, scaly papules and plaques with long axes oriented along the skin-cleavage lines in those areas.⁶ Guttate psoriasis is a common form of psoriasis in children in whom there is evidence of a preceding upper respiratory tract infection. Small discrete, erythematous, and scaly papules and plaques usually develop on the trunk and extremities. In children, spontaneous remission occurs within weeks to months, while adults might have a more chronic course.⁷ Sarcoidosis is a systemic, idiopathic, granulomatous disorder; common cutaneous manifestations include erythema nodosum and red to violaceous papules and plaques on the face, trunk, and extremities.⁸ Results of histology show noncaseating epithelioid granulomas.⁸ In difficult cases, histologic examination of affected skin might be required to make the distinction among possible diagnoses.

Management

Early diagnosis of tumid LE—and exclusion of other forms of LE—is the first step in optimal management. Use of topical corticosteroids, in conjunction with the avoidance of ultraviolet radiation, often results in complete resolution of the lesions, as was the case with our patient. In difficult cases, antimalarial agents can also be used.^2–5