B43 Chromomycosis and pheomycotic abscess

Name of the Condition

• Chromomycosis and pheomycotic abscess
• ICD-10-CM Code B43

Summary

Chromomycosis and pheomycotic abscess are rare fungal infections characterized by chronic, localized skin and subcutaneous tissue involvement. These conditions result from the infiltration of dematiaceous fungi, leading to the formation of nodules, plaques, or abscesses. The infections typically progress slowly and may persist for years if untreated.

Causes

The infections are caused by a group of fungi known as dematiaceous (or "black") 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 in advanced cases.

Diagnosis

Diagnosis involves a combination of clinical evaluation and laboratory testing. A physical examination assesses lesion characteristics, followed by biopsy to identify fungal elements under microscopy. Fungal cultures and molecular tests confirm the specific species, while imaging may evaluate deeper tissue involvement.

Treatment Options

• Long-term antifungal therapy, such as itraconazole or terbinafine, to target the causative fungi.
• Surgical excision or debridement of localized lesions for severe or refractory cases.
• Adjunctive therapies, including cryotherapy or heat therapy, to enhance treatment response.
• Monitoring for treatment efficacy and recurrence, especially in immunocompromised patients.

Prognosis and Follow-Up

Prognosis depends on early diagnosis, treatment adherence, and immune status. With appropriate therapy, lesions often improve, but complete resolution may take months. Regular follow-up is essential to monitor for recurrence or complications, particularly in immunocompromised individuals.

Complications

• Chronic, progressive skin damage or disfigurement.
• Secondary bacterial infections of ulcerated lesions.
• Lymphatic spread or deeper tissue invasion in untreated cases.
• Increased risk of recurrence in immunocompromised patients.

Lifestyle & Prevention

• Avoid direct contact with soil or decaying organic material, especially with open skin wounds.
• Use protective clothing (e.g., gloves, boots) during activities with high exposure risk.
• Promptly clean and treat minor skin injuries to reduce fungal entry.
• Maintain good overall health to support immune function.

When to Seek Professional Help

Seek medical attention if you develop persistent, slow-growing skin lesions, especially after potential exposure to soil or organic material. Early evaluation is critical for accurate diagnosis and timely treatment to prevent complications.

Tips for Medical Coders

Document the clinical presentation, including lesion characteristics (e.g., nodules, abscesses, pigmentation) and any confirmed fungal identification. Specify the affected body area and note relevant risk factors (e.g., occupational exposure, immunocompromised status) to support code assignment. Ensure documentation aligns with the broad scope of B43, which encompasses both chromomycosis and pheomycotic abscess.