Cutaneous tuberculosis in Hong Kong: an update

Area of Science:

• Dermatology
• Infectious Diseases
• Microbiology

Background:

• Cutaneous tuberculosis (TB) presents diverse clinical manifestations.
• Understanding the epidemiology and specific forms of cutaneous TB is crucial for diagnosis and treatment.

Purpose of the Study:

• To update the epidemiological data on cutaneous tuberculosis in Hong Kong.
• To analyze the clinical characteristics, diagnostic methods, and treatment responses for various forms of cutaneous TB.

Main Methods:

• A retrospective study was conducted reviewing 147 patients with cutaneous tuberculosis from 1993 to 2002.
• Data collected included patient demographics, clinical presentation, diagnostic results (histology, microbiology), and treatment outcomes.
• Focus was placed on differentiating true cutaneous TB from tuberculids.

Main Results:

• Erythema induratum was the most prevalent form (86%), predominantly affecting the lower limbs in females.
• True cutaneous tuberculosis cases included lupus vulgaris and tuberculosis verrucosa cutis (4% each).
• Diagnostic methods like culture and polymerase chain reaction (PCR) showed positivity in less than half of the cases; all patients responded well to anti-TB therapy.

Conclusions:

• Lupus vulgaris and tuberculosis verrucosa cutis are the most common types of true cutaneous tuberculosis.
• Erythema induratum is the most frequent tuberculid presentation.
• Diagnostic yield of culture and PCR for cutaneous TB is limited in this cohort.