Lupus vulgaris: a narrative review

Area of Science:

• Dermatology
• Infectious Diseases
• Microbiology

Background:

• Lupus vulgaris (LV) is a paucibacillary cutaneous tuberculosis variant.
• It arises in sensitized individuals with robust immunity to tuberculosis.
• Diverse presentations of LV can complicate diagnosis.

Purpose of the Study:

• To provide a comprehensive review of lupus vulgaris.
• To enhance dermatologist understanding of LV diagnosis and therapy.
• To detail the introduction, pathogenesis, clinical features, and management of LV.

Main Methods:

• Review of existing literature on lupus vulgaris.
• Discussion of diagnostic modalities including Tuberculin test, histopathology, dermoscopy, polymerase chain reaction (PCR), and culture.
• Analysis of clinical features, differential diagnoses, complications, and treatment options.

Main Results:

• Tuberculin test is strongly positive in LV.
• Histopathology reveals epithelioid granulomas; acid-fast bacilli are rarely seen.
• Dermoscopy shows characteristic linear vessels on a yellow-orange background.
• Culture has a low positivity rate, while PCR can detect Mycobacterium tuberculosis.
• A combination of diagnostic methods aids in LV diagnosis.

Conclusions:

• Accurate diagnosis of LV relies on integrating clinical presentation with investigations like histopathology, dermoscopy, and molecular tests.
• Prompt and appropriate treatment is essential to manage lupus vulgaris and prevent complications.