Clinical presentation
A 50-year-old woman with no previous medical history presented with an alopecic patch that had been evolving for 1 year. Physical examination revealed a left temporal alopecic plaque 7 cm in diameter with erythema and telangiectasia. The lesion was the site of yellowish comedones. The rest of the physical examination was unremarkable, and systematic assessment result was negative (Fig 1).
Fig 1.
Left temporal alopecic plaque 7 cm in diameter with erythema, telangiectasia, and comedones.
Dermoscopic appearance
In the periphery of the lesion, dermoscopic examination revealed yellow-brownish keratotic plugs, whitish rosettes, and telangiectatic vessels against a congestive erythematous background. The cicatricial areas were the site of scattered dark-brown discoloration and white structureless areas forming a speckled pattern. There were no scales or whitish perifollicular halo (Figs 2 and 3).
Fig 2.
Dermoscopic image showing yellow-brownish keratotic plugs (black arrows), whitish rosettes (black circles), erythema (white asterisks), and brownish pigmentation (white arrows).
Fig 3.
Dermoscopic image showing scarring alopecia, scattered dark-brown discoloration, and white structureless areas (black bars for measuring size).
Histologic diagnosis
Histologic examination showed hyperkeratosis, follicular keratotic plugs, and focal basal vacuolization of the epidermis and follicular epithelium. Direct immunofluorescence staining result for immunoglobulin M was positive. These features were consistent with comedonal lupus (Fig 4).
Key message.
Comedonal lupus is a rare variant of chronic cutaneous erythematous lupus that has been occasionally reported in the literature.1 Dermoscopic features depend on the stage of the disease. At the initial stage, we noted the presence of keratotic plugs, megapoints, whitish rosettes corresponding to follicular hyperkeratosis, and plugging of the ostia with keratotic material upon histopathologic examination. Megacapillaries and telangiectatic vessels were secondary to the extravasation of red blood cells. At a later stage, we found perifollicular whitish halos, reflecting fibrosis. The final stage was characterized by the disappearance of keratotic plugs, presence of white structureless areas, and scattered dark-brown discoloration forming a speckled pattern. These findings are secondary to pigmentary incontinence and scarring alopecia.2
Fig 4.
Histologic image of follicular keratotic plugs and focal basal vacuolization of the epidermis and follicular epithelium. (Hematoxylin-eosin stain; original magnification: ×20.)
Conflicts of interest
None disclosed.
Footnotes
Funding sources: None.
IRB approval status: Not applicable.
References
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