Leprosy with Atypical Skin Lesions Masquerading as Relapsing Polychondritis

Area of Science:

• Rheumatology
• Infectious Diseases
• Dermatology

Background:

• Rheumatic manifestations, including arthritis, are the third most common presentation of leprosy after skin and nerve involvement.
• Leprosy exhibits diverse clinical features influenced by individual immune status.
• Relapsing polychondritis is an autoimmune condition characterized by episodic inflammation of cartilaginous tissues, notably affecting the ears.

Observation:

• A unique case of a 22-year-old patient presented with external ear inflammation resembling relapsing polychondritis, accompanied by inflammatory arthritis and skin lesions.
• The patient's ear involvement was painless and affected the ear lobules, distinguishing it from the painful, lobule-sparing ear inflammation typical of relapsing polychondritis.
• Histopathology confirmed leprosy, despite the atypical presentation of the ear and skin lesions.

Findings:

• Leprosy can present with extralesional manifestations that closely mimic other autoimmune diseases like relapsing polychondritis.
• Atypical ear involvement, including painless inflammation of the lobules, can be a presenting sign of leprosy.
• Histopathological examination is essential for accurate diagnosis when clinical features are non-classical.

Implications:

• This case highlights the importance of considering infectious etiologies, such as leprosy, in patients presenting with apparent autoimmune conditions.
• Prompt and accurate diagnosis through tissue biopsy can prevent the inappropriate use of immunosuppressive therapy, which could exacerbate underlying infections.
• Clinicians should maintain a broad differential diagnosis for inflammatory conditions affecting the ears and joints, especially in endemic areas for leprosy.