Lupus vulgaris as a form of cutaneous TB caused by the Bacille Calmette-Guérin vaccine

a pediatric case

Abstract

Cutaneous TB is a rather unusual chronic infectious disease caused by Mycobacteriun tuberculosis. There are several forms of cutaneous infection, lupus vulgaris being the most frequent and ordinary one in developed countries. Clinical variations will depend on the site of infiltration of the skin by the bacillus, the patient’s immune condition and the environment. In the case of lupus vulgaris, apart from Mycobacteriun tuberculosis, M. bovis may be involved, and the Bacille Calmette Guérin involvement is less frequent. The latter presents a chronic evolution, being progressive and unusual in children.

The study presents the case of a girl who was diagnosed with a form of cutaneous tuberculosis called lupus vulgaris caused by the Bacille Calmette-Guérin vaccine.

Clinical case:

a 10 year old girl who evidenced skin lesions of different kinds, of slow evolution and asymptomatic: the largest one was in the external part of the right deltoid muscle as an erythematous plaque of 20 by 10 cm with higher borders evidencing micro papules in the center that coalesce leaving a central atrophy zone. The latter had started in the neonatal stage after the Bacille Calmette-Guérin vaccine. For three years she had evidenced a second smaller lesion in the outer face of the right thigh of similar characteristics and other multiple lesions in the back with the shape of vinous red micro papules. Assessment tests were generally normal, as well as the chest and limbs X-ray. The tuberculin test evidenced a 15 mm induration and smears were negative. The deltoid muscle skin lesion biopsy showed caseous granulomas and molecular techniques diagnosed attenuated Mycobacteriumbovis. Given that diagnose the patient received anti-TB treatment during 10 months, tolerance being good and the lesions improved.