C. Linear or annular lupus erythematosus panniculitis of the scalp
Histopathologic examination revealed prominent lymphocytic infiltration around the hair follicles and appendages in the dermis, and vacuolar degeneration in the basal layer of the hair follicles without epidermal involvement. In the subcutaneous tissue layer, a lobular lymphocytic infiltrate was present with associated hyaline fat necrosis (Figure, C and D). Abundant mucin deposition in the deep dermis and subcutaneous fat layer were highlighted by Alcian blue staining. Direct immunofluorescence results were positive, with granular deposition of immunoglobulin (Ig) G, IgA, IgM, C3, C1q, and fibrinogen in the dermal blood vessels. All laboratory test findings were normal, including negativity for antinuclear antibody and antidouble-stranded DNA antibody. A diagnosis of lupus erythematosus panniculitis (LEP), specifically linear or annular lupus erythematosus panniculitis of the scalp (LALPS), was made. Slight improvement of the depressed skin lesion was observed with oral hydroxychloroquine (400 mg/d) and topical corticosteroid for 3 months.