Dermoscopy of the diverse spectrum of cutaneous tuberculosis in the skin of color

Abstract

Introduction: Cutaneous tuberculosis is an uncommon form of tuberculosis, accounting for 1-2% of all forms of extra-pulmonary tuberculosis. Knowledge of the dermoscopy characteristics of different clinical types of cutaneous tuberculosis can help timely diagnosis resulting in better outcomes. Materials and methods: All clinically suspected and biopsy confirmed cases of cutaneous tuberculosis seen from July 2019 through December 2021 were retrospectively recruited. Information including age, gender, disease duration, site and morphology of lesions, and presence of concomitant tuberculosis elsewhere was noted. Two investigators retrospectively reviewed the dermoscopic characteristics of these cases. Results: Twenty-two patients comprised of 12 women and ten men met the inclusion criteria. Lupus vulgaris was the commonest presentation of cutaneous tuberculosis seen in 13 patients. Five had scrofuloderma, two had tuberculosis verrucosa cutis and one patient each had lichen scrofulosorum and papulo-necrotic tuberculid. Yellow-orange structureless areas (100%), linear/dot vessels (100%), white scales (92.3%), and white structureless areas (84.6%) were the predominant dermoscopy findings in lupus vulgaris. In scrofuloderma, linear vessels and white structureless areas were visible in all cases. Dirty white scales with a papillated surface were characteristically seen in tuberculosis verrucosa cutis, with one of the two patients each showing vessels and yellow-orange structureless areas. White globules with surrounding erythema were seen in lichen scrofulosorum and yellow-orange structureless areas with keratin plugs in papulo-necrotic tuberculid. Conclusion: A thorough understanding of the characteristic dermoscopy of cutaneous tuberculosis can help suspect the diagnosis early resulting in better management opportunity.

Lupus vulgaris: a narrative review

“…There can also be whitish reticular streaks and milia-like cysts. [18][19][20][21][22] These dermoscopic features are nonspecific, as similar findings can be present in other granulomatous dermatoses like granuloma annulare and sarcoidosis. The other dermoscopic features seen are a perilesional halo of pigmentation, white structureless areas, white lines, focal white scale, red globules, ulceration, and follicular plugging.…”

“…The orange‐yellow background corresponds to the granulomas in the dermis. There can also be whitish reticular streaks and milia‐like cysts 18–22 . These dermoscopic features are nonspecific, as similar findings can be present in other granulomatous dermatoses like granuloma annulare and sarcoidosis.…”

“…The combination of these features helps to diagnose lupus vulgaris. 22,23 Thus, dermoscopy can be a valuable tool in diagnosing lupus vulgaris in addition to other methods.…”

“…The other dermoscopic features seen are a perilesional halo of pigmentation, white structureless areas, white lines, focal white scale, red globules, ulceration, and follicular plugging. The combination of these features helps to diagnose lupus vulgaris 22,23 . Thus, dermoscopy can be a valuable tool in diagnosing lupus vulgaris in addition to other methods.…”

Dermoscopic features of lichen nitidus

“…The typical clinical differential diagnoses of lichen nitidus include keratosis pilaris, lichen spinulosus, lichen scrofulosorum and plane warts (verruca plana). The dermoscopic features of these disorders are presented in table 1 3–5. Our index case, therefore, illustrates the significance of dermoscopy in averting the skin biopsy in lichen nitidus, particularly the young children.…”