B43.0 Cutaneous chromomycosis

Name of the Condition

• Cutaneous chromomycosis
• ICD-10-CM Code B43.0

Summary

Cutaneous chromomycosis is a chronic fungal infection affecting the skin and subcutaneous tissues. It is characterized by slow-growing, localized lesions caused by dematiaceous fungi. The infection typically progresses over months to years and may present as nodules, plaques, or ulcerated areas. Without treatment, the condition can persist and lead to tissue damage.

Causes

The infection is caused by dematiaceous (pigmented) fungi, which are found in soil, decaying vegetation, or organic matter. These fungi enter the body through minor skin trauma, such as cuts or puncture wounds, and establish chronic infections in the skin and subcutaneous tissues.

Risk Factors

• Occupational or recreational exposure to soil, wood, or decaying organic material.
• Immunocompromised status, including conditions like HIV/AIDS or immunosuppressive therapy.
• Living in or traveling to tropical or subtropical regions where these fungi are endemic.
• Minor skin injuries or breaks that allow fungal entry.

Symptoms

• Slow-growing, painless or mildly tender nodules, plaques, or abscesses on the skin.
• Lesions may become verrucous (wart-like) or ulcerated over time.
• Dark pigmentation or discoloration of affected skin areas.
• Possible lymphatic involvement or satellite lesions.

Diagnosis

Diagnosis involves a physical examination of skin lesions, followed by biopsy to identify fungal elements under microscopy. Fungal cultures and molecular tests may be used to confirm the specific fungal species. Imaging may be performed to assess deeper tissue involvement.

Treatment Options

• Antifungal medications, such as itraconazole or terbinafine, are the primary treatment.
• Surgical excision may be considered for localized or refractory lesions.
• Long-term therapy is often required to prevent recurrence.

Prognosis and Follow-Up

With appropriate treatment, the prognosis is generally good, though relapses can occur. Follow-up is necessary to monitor for recurrence or treatment response. Chronic infections may require extended antifungal therapy.

Complications

• Chronic tissue damage or scarring.
• Secondary bacterial infections.
• Dissemination to deeper tissues in immunocompromised individuals.

Lifestyle & Prevention

• Avoid contact with soil or decaying organic matter, especially if skin is broken.
• Wear protective clothing (e.g., gloves, boots) during outdoor activities.
• Keep skin clean and intact to reduce the risk of fungal entry.

When to Seek Professional Help

Seek medical attention if you develop persistent skin lesions, especially after exposure to soil or organic material, or if lesions worsen despite home care.

Tips for Medical Coders

Document the clinical presentation, including lesion characteristics and exposure history, to support the diagnosis of cutaneous chromomycosis. Ensure the code B43.0 is used for cutaneous involvement only; specify additional details if deeper tissue or systemic involvement is present.