Answer to Dermacase continued from page 795
3. Lupus miliaris disseminatus faciei
Lupus miliaris disseminatus faciei (LMDF), also known as acnitis, is an uncommon chronic inflammatory skin disorder that typically affects young adults.1–5 Clinically, it is characterized by progressive, asymptomatic, single or grouped, red to yellowish-brown papules, which might occasionally become pustular. It usually involves the central face, especially the periorbital areas.1–5 Less commonly, it might involve the trunk and extremities. Spontaneous resolution occurs after 1 to 3 years with crusting of papules, which can later leave residual disfiguring scars.1–5 Histology reveals a superficial granulomatous inflammatory pattern with formation of caseating granulomas, as was the case in our patient. Results of acid-fast staining are negative in cases of LMDF.
The pathogenesis of LMDF is still unclear. Some have suggested that underlying causes might include infections, foreign body reactions, ruptured epidermal cysts, or reaction to Demodex folliculorum. While many consider the condition to be a distinct inflammatory and cutaneous entity, others have suggested that it might be a type of tuberculid or even a variant of granulomatous rosacea.1–5
Differential diagnosis
Clinical differential diagnosis includes acne vulgaris, milia, and syringomas.6–8 Acne vulgaris is usually characterized by the presence of both non-inflammatory (comedones) and inflammatory (papules, pustules, nodules, or cysts) lesions, the former being absent in LMDF.6 Milia are benign, small, white, keratinous cysts, superficial in nature, that commonly present on the cheeks, eyelids, and, genitalia of children and young adults.7 Syringomas are benign sporadic adnexal tumours, a few millimetres in diameter, that present most commonly as multiple smooth, firm, slightly yellowish or skin-coloured papules over the face, especially the lower eyelids of adult women.8
Management
The first step in the management of this disorder is to exclude tuberculosis via chest x-ray scans and tuberculin testing, especially if histology results show the presence of caseating granulomas. Several topical and oral agents, including antibiotics such as tetracyclines, have been used in the treatment of this condition, with variable results. Our patient responded to a 2-month course of doxycycline (100 mg twice daily for 2 months) with complete resolution of the lesions.
Footnotes
-
Competing interests
None declared
- Copyright© the College of Family Physicians of Canada