Cutaneous tuberculosis in children and adolescents: a clinicohistological study

Resurgence of tuberculosis (TB) in the era of human immunodeficiency virus (HIV) has rejuvenated the interest in this global health problem. Cutaneous TB, an important extra-pulmonary form in children, is commonly seen in our dermatological practice. As detection of acid-fast bacillus (AFB) on smear or culture is not always positive, histopathology is necessary to help in diagnosing and classifying the variants of skin TB. The current study was conducted to analyse the clinicopathological characteristics of cutaneous TB in children and adolescents.

This prospective study included 103 patients (age<19 years). A detailed history and clinical examination was followed by complete investigative work up including fine needle aspiration cytology and culture. Histopathological evaluation was performed specifically noting the epidermal and dermal features. The patients were followed up regularly for one year after the start of treatment.

The different patterns of cutaneous TB seen were, scrofuloderma 38 (36.9%), lichen scrofulosorum 34 (33%), lupus vulgaris 22 (21.3%), TB verrucosa cutis 4 (3.9%), papulonecrotic tuberculid 4 (3.9%) and erythema nodosum 3 (2.9%). Systemic associations were seen in 55 (53.4%) patients, namely TB lymphadenitis in 30 (29.2%), pulmonary TB in 13 (12.6%), abdominal TB in 6 (5.8%) and TB arthritis in 6 (5.8%). The histopathological corroboration of clinical diagnosis was seen in 65.7% of cases of scrofulodermas, 72.7% of cases of lupus vulgaris and 67.6% of cases of lichen scrofulosorum.

A large spectrum of clinical patterns and histological characteristics of cutaneous TB exists in children. Lichen scrofulosorum is more commonly seen in comparison to adults. Systemic involvement was a feature in a major proportion of our patients.