Tinea ICD-10 Codes: Corporis, Pedis, Cruris & More

Tinea, commonly known as ringworm, is a fungal infection of the skin caused by dermatophytes. Accurate medical coding is essential for proper diagnosis, treatment, and insurance reimbursement. This guide provides a comprehensive overview of tinea ICD-10 codes for all types, including tinea corporis, tinea pedis, tinea cruris, and others. Whether you are a healthcare provider, coder, or student, understanding these codes will streamline your documentation and ensure compliance.

The ICD-10-CM system categorizes tinea infections under the B35 code range (dermatophytosis). Each type of tinea has a specific subcode based on the affected body site. Below, we break down the most common types, their corresponding codes, and coding tips to avoid common errors.

Tinea Corporis ICD 10

Tinea corporis, or ringworm of the body, presents as annular, scaling plaques on the trunk, arms, or legs. The correct tinea corporis ICD 10 code is B35.4. This code is used when the infection occurs on skin surfaces other than the scalp, bearded areas, groin, hands, feet, or nails. When documenting, specify the location (e.g., “tinea corporis of the arm”) but always use B35.4 as the primary code.

Common clinical features include itching, redness, and a raised border. Differential diagnoses include eczema, psoriasis, and granuloma annulare. Accurate coding helps track epidemiological data and supports appropriate antifungal therapy coding.

• Code: B35.4 – Tinea corporis
• Excludes1: tinea of other specific sites (B35.0-B35.3, B35.5-B35.9)
• Note: Use additional code for any associated fungal infection if applicable.

Tinea Pedis ICD 10

Tinea pedis, commonly known as athlete's foot, affects the feet and is one of the most prevalent fungal infections. The tinea pedis ICD 10 code is B35.3. This code covers infections of the foot, including interdigital spaces, soles, and heels. It is important to distinguish tinea pedis from other foot conditions like contact dermatitis or bacterial infections.

There are three clinical forms: interdigital (most common), moccasin-type (chronic, diffuse scaling), and vesiculobullous. Coders should document the type if known, as it may guide treatment but does not affect the code. For bilateral involvement, simply document “bilateral tinea pedis” – the code B35.3 remains the same.

• Code: B35.3 – Tinea pedis
• Excludes1: tinea manuum (B35.2)
• Clinical Tip: Often coexists with tinea manuum due to same dermatophyte.

Tinea Cruris ICD 10

Tinea cruris, known as jock itch, affects the groin, inner thighs, and perineal area. The correct tinea cruris ICD 10 code is B35.6. This condition is more common in men and often exacerbated by sweating and tight clothing. The code B35.6 specifically excludes tinea of other sites; if the infection extends to the buttocks, still use B35.6 as primary, with additional codes if needed.

Presentation includes erythematous, well-demarcated plaques with central clearing and satellite lesions. It is crucial to differentiate from candidal intertrigo or erythrasma. Coding accurately for tinea cruris supports appropriate antifungal prescribing (e.g., terbinafine or azoles) and helps avoid misdiagnosis.

• Code: B35.6 – Tinea cruris
• Excludes1: tinea of other sites (B35.0-B35.5, B35.7-B35.9)
• Common Comorbidity: Often occurs with tinea pedis – code both conditions.

Other Common Tinea ICD-10 Codes

The tinea ICD-10 category includes several other types. Below is a list of important codes for completeness:

• B35.0 – Tinea barbae and tinea capitis (ringworm of bearded area and scalp)
• B35.1 – Tinea unguium (onychomycosis – nail infection)
• B35.2 – Tinea manuum (ringworm of hand)
• B35.5 – Tinea imbricata (concentric ringworm, tropical)
• B35.8 – Other dermatophytoses (e.g., tinea faciei)
• B35.9 – Dermatophytosis, unspecified

General Coding Guidelines for Tinea ICD-10

When using ICD-10 codes for tinea, follow these principles:

• Specificity: Code to the highest level of specificity. For example, use B35.4 for tinea corporis, not the general B35.9.
• Laterality: Some codes may require laterality for certain sites (e.g., hand or foot), but B35.3 (pedis) and B35.2 (manuum) are not laterality-specific. If bilateral, simply state bilateral.
• Associated Conditions: If the tinea infection is superimposed on another condition (e.g., eczema herpeticum), code both, sequencing the primary reason for encounter.
• Acute vs. Chronic: ICD-10-CM does not differentiate between acute and chronic for tinea codes; the same code applies regardless of duration.

Common Documentation Errors

To minimize errors when coding tinea ICD-10, avoid these pitfalls:

• Using unspecified code B35.9 when the site is known. Always use site-specific codes.
• Assigning multiple codes for the same lesion (e.g., tinea corporis and tinea cruris if the groin and body are both involved – it is possible but document clearly).
• Missing addition of external cause codes if the infection was acquired in a specific setting (e.g., gym) – not typically required for tinea.

Proper documentation includes the type of tinea, site, and any complicating factors such as secondary bacterial infection. Using standardized terminology (e.g., “tinea pedis” rather than “athlete’s foot”) aids coding accuracy.

Practical Examples

To illustrate correct coding, here are examples:

• Example 1: Patient presents with ringworm on the arm. Diagnosis: tinea corporis. Code: B35.4.
• Example 2: Patient with athlete’s foot and jock itch. Diagnoses: tinea pedis, tinea cruris. Codes: B35.3, B35.6.
• Example 3: Fungal nail infection of the toenail. Diagnosis: tinea unguium. Code: B35.1.

These examples emphasize the importance of site-specific tinea ICD-10 coding. Always refer to the ICD-10-CM manual for the most current updates, as codes may change annually.

Conclusion

Mastering ICD-10 codes for tinea is essential for accurate medical billing and epidemiological tracking. From tinea corporis (B35.4) to tinea cruris (B35.6) and tinea pedis (B35.3), each code captures a specific clinical presentation. By following coding guidelines and avoiding common errors, healthcare professionals can ensure compliance and optimize reimbursement. For the most up-to-date coding information, consult the latest ICD-10-CM manual or trusted coding resources.