Dermoscopy of Lichen Scrofulosorum

Lichen scrofulosorum is a tuberculid usually seen in children and the adolescent age group.[1,2] We report the dermoscopic features of two children with clinically and histopathologically diagnosed lichen scrofulosorum.

A 7-year-old boy, an untreated case of tuberculous lymphadenitis was referred to us with multiple, asymptomatic, grouped skin colored follicular and perifollicular pinhead-sized papules over the trunk, arms and back since the past 3 months [Figure 1a]. Another 10-year-old girl presented with asymptomatic erythematous to skin colored shiny papules on trunk for the past 5 months similar in morphology as the first case, with an unknown primary focus of tuberculosis for which the child was thoroughly evaluated [Figure 1b]. Dermoscopy of both the cases showed pale round monomorphic grouped perifollicular dots with a central brown follicular plug and marginal rim of fine white scaling [Figure 2]. The second case showed more extensive scaling and marginal hyperpigmentation [Figure 2b]. Histopathology of both the cases showed ill defined, non-necrotizing epitheloid cell perivascular granulomas [Figure 3]. Ziehl Neelsen stains was negative for acid fast bacilli. In view of the classic morphology and histopathology, both the children were diagnosed as lichen scrofulosorum and both the patients were started on anti-tubercular therapy.

Figure 1.

(a) Grouped skin colored follicular and perifollicular pinhead-sized papules over the trunk. (b) Dermoscopy showed pale round monomorphic grouped perifollicular large dots with a central black follicular opening topped with a crust and marginal rim of fine white scaling (10×, DL3N Polarized)

Figure 2.

(a) Erythematous to shiny colored grouped papules over trunk. (b) Dermoscopy showed pale round monomorphic grouped perifollicular large dots with a central black follicular plug with extensive scaling and marginal hyperpigmentation (10×, DL3N Polarized)

Figure 3.

Microphotographs showed ill-defined granuloma with epithelioid cell and lymphocytes. (H and E, 40×)

To the best of our knowledge, this is the first report describing the dermoscopic features of lichen scrofulosorum. It has to be differentiated from the dermoscopic findings of other common follicular lesions like keratosis pilaris[3](coiled hair, follicular plug, and marginal erythema), lichen nitidus[4](ill-defined hypopigmentation with diffuse erythema, linear vessels within the lesion, Peripheral scaling), follicular psoriasis[5](perifollicular scaling, red dots/dotted vessels, red globules, twisted red loops, white homogenous area with normal hair). Pale dots in dermoscopy corresponds to granulomatous infiltration in the perifollicular lesion on histopathology.

Although, histopathology and culture remain the gold standard for confirming a diagnosis of cutaneous tuberculosis, a non-invasive visual aid like dermoscopy may help in clinical diagnosis as well as in choosing a representative area for the biopsy.

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The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

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Conflicts of interest

There are no conflicts of interest.