Lymphatic spread in an immunocompetent adult

Introduction: Cutaneous tuberculosis with lymphatic spread is rarely described. Observation: We report the case of a woman aged 38, immunocompetent, working in a fruit sorting center, who consulted us for ulceration of the left third finger that had persisted for four months, following a prick from a prickly pear. Physical examination revealed a nodular, erythematous, and ulcerative lesion of the left third finger, associated with inflammatory subcutaneous nodules arranged in a line along the ipsilateral upper extremity and an ipsilateral axillary lymph node. Laboratory tests and chest X-ray were normal. Discussion: Pathological examination revealed granulomatous chronic inflammation without necrosis. PCR detected DNA from Mycobacterium tuberculosis. No extracutaneous tuberculosis locations were detected. A tuberculous chancre by direct inoculation was therefore diagnosed. The patient received quadruple therapy (rifampicin + isoniazid + pyrazinamide + ethambutol) for 2 months, followed by a combination therapy based on isoniazid and rifampicin for 6 months. Marked regression of the cutaneous lesions occurred after 1 month of firstline therapy. Conclusion: A tuberculous chancre is a rare form of cutaneous tuberculosis, with possible lymphatic spread, in immunocompromised patients but also in immunocompetent children and young adults.