B35.5 Tinea imbricata

Name of the Condition

• Tinea imbricata
  
  • Also known as tokelau

Summary

Tinea imbricata is a chronic fungal infection of the skin caused by Trichophyton concentricum. It is characterized by distinctive, concentric, scaly patches that may cover large areas of the body. The condition is more common in tropical and subtropical regions and can persist for years without treatment.

Causes

Tinea imbricata is caused by the dermatophyte fungus Trichophyton concentricum. The fungus invades the outer layers of the skin (stratum corneum) and spreads through direct contact with infected individuals or contaminated objects. It thrives in warm, humid environments.

Risk Factors

• Living in or traveling to tropical or subtropical regions where the fungus is endemic
• Close contact with infected persons
• Poor hygiene or overcrowded living conditions
• Weakened immune system (e.g., due to illness or medication)

Symptoms

• Multiple, concentric, scaly patches on the skin (resembling layered scales)
• Patches may be itchy or asymptomatic
• Lesions typically start on the trunk and may spread to other areas
• Skin may appear dry, thickened, or discolored in affected regions

Diagnosis

Diagnosis is based on clinical appearance and confirmed by microscopic examination of skin scrapings (KOH test) or fungal culture. The characteristic concentric scaling pattern is a key diagnostic clue. Biopsy may be performed in atypical cases.

Treatment Options

• Oral antifungal medications (e.g., griseofulvin, terbinafine) for systemic treatment
• Topical antifungals (e.g., clotrimazole, miconazole) for localized or mild cases
• Long-term treatment may be required due to the chronic nature of the infection

Prognosis and Follow-Up

With appropriate treatment, the prognosis is generally good, though recurrence is possible. Follow-up is recommended to monitor for resolution and to address any persistent symptoms. Untreated cases may persist for years.

Complications

• Chronic infection leading to extensive skin involvement
• Secondary bacterial infections from scratching
• Social or psychological impact due to visible skin changes

Lifestyle & Prevention

• Maintain good hygiene practices
• Avoid sharing personal items (e.g., towels, clothing) with infected individuals
• Keep skin dry and clean, especially in humid environments
• Seek prompt treatment if symptoms appear to prevent spread

When to Seek Professional Help

Consult a healthcare provider if you notice persistent, scaly skin patches, especially if they are itchy or spreading. Early diagnosis and treatment can help prevent complications and reduce the risk of transmission.

Tips for Medical Coders

When coding for tinea imbricata, use ICD-10-CM code B35.5. Ensure documentation supports the diagnosis, including clinical findings (e.g., concentric scaling) and any relevant history (e.g., travel to endemic regions). Confirm that the code is not used for other dermatophyte infections unless specifically indicated.