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Intradermal Inoculation of Mycobacterium avium in the Mouse Ear
Published on: July 3, 2025
Cutaneous tuberculosis of the pinna: a report of two cases
Sowmya Kaimal1, Vijay Aithal, Muthu Sendhil Kumaran
1Department of Dermatology, St John's Medical College Hospital, Bangalore, India. sowmyakaimal@hotmail.com
Background:
Cutaneous tuberculosis (TB) is less common than other forms of TB but accounts for 1.5% of all cases of extrapulmonary TB. The source of mycobacterial infection and the immune status of the host determine the presentation of any of a wide spectrum of clinical manifestations. Lupus vulgaris (LV) is a post-primary, paucibacillary form of TB caused by hematogeneous, lymphatic, or contiguous spread from elsewhere in the body.
Methods:
We report two recent cases of LV in women presenting with the exclusive involvement of the ear lobe. In Patient 1, clinical presentation appeared as an apparently benign chronic eczematous process. In Patient 2, it appeared as a fulminant ulceronecrotic process. Both women were immunocompetent, and neither had a personal or family history of TB.
Results:
Both patients were diagnosed with LV and treated with standard antitubercular therapy (ATT). In both patients, mycobacterial culture showed growth of Mycobacterium tuberculosis sensitive to streptomycin, rifampicin, and ethambutol.
Conclusions:
Lupus vulgaris is the most common form of cutaneous TB. It is important to diagnose LV because it can result in chronic disfigurement and because 10-20% of LV patients have active pulmonary TB or TB of the bones and joints. In addition, longstanding LV is known to lead to the development of squamous cell carcinoma, which can be avoided by early diagnosis and treatment with ATT.
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