bubble_chart Overview

Tinea corporis refers to a dermatophyte infection that occurs on the smooth skin, excluding the scalp, hair, palms, metatarsus, and nail plates.

bubble_chart Etiology

Disease cause: In China, it is mainly caused by Trichophyton rubrum, Trichophyton mentagrophytes, Microsporum canis, and Epidermophyton floccosum. Occasionally, it is caused by Trichophyton schoenleinii, Microsporum ferrugineum, etc.

This disease is primarily transmitted through direct contact with infected individuals or domesticated animals (such as dogs, cats, etc.) with tinea, or indirect contact with contaminated clothing. It can also result from self-infection (such as pre-existing tinea of the hands, feet, or nails). Long-term use of glucocorticoids, or conditions like diabetes and chronic wasting diseases, increase susceptibility to this condition. Warm climates and humid environments further facilitate its occurrence.

bubble_chart Clinical Manifestations

Tinea corporis commonly occurs on the face, neck, waist, abdomen, buttocks, and limbs. The primary lesions are papules, papulovesicles, or vesicles, ranging from pinhead to mung bean size, gradually expanding outward from the center to form annular or polycyclic patterns. The edges are slightly raised, narrow, and discontinuous, with reduced central inflammation accompanied by scaling or pigmentation. Due to differences in pathogenic fungi and individual variations, skin lesions may vary. For example, lesions caused by anthropophilic Trichophyton rubrum often appear as large patches with fewer numbers, while lesions caused by zoophilic Microsporum canis or Microsporum gypseum exhibit more pronounced inflammation, often dominated by vesicles, with fewer lesions but greater numbers. Patients experience cutaneous pruritus, and chronic cases may develop localized eczema-like changes or secondary bacterial infections due to frequent scratching. This condition can occur at any age but is more common in young and middle-aged males. Symptoms often flare up or worsen in summer and alleviate or subside in winter.

Tinea cruris can occur unilaterally or bilaterally, with basic lesions similar to tinea corporis. However, due to the warm, moist, and friction-prone nature of the area, it often presents as erythema with clearly defined borders and marked inflammation on the lower side. In chronic cases, the lesions may lose their typical appearance or become infiltrated, thickened, and lichenified due to scratching.

bubble_chart Diagnosis

Based on the typical skin lesion manifestations, diagnosis is generally not difficult. A fungal direct microscopic examination of scales from the lesion edge can confirm the diagnosis, but a negative result often cannot rule it out. Sometimes repeated examinations or fungal culture are necessary.

bubble_chart Treatment Measures

1. The main treatment is medication. Depending on the situation, external application of compound benzoic acid liniment (Whitfield's solution), compound resorcinol liniment (Castellani's paint), 3% miconazole cream, 1-2% clotrimazole cream, ketoconazole cream, etc., can be used twice daily for 2-4 weeks. Continue medication for 2 weeks after the skin lesions subside to prevent recurrence. For tinea cruris and tinea corporis in infants and young children, milder medications should be selected.
2. For extensive skin lesions or cases where topical treatment alone is ineffective, oral griseofulvin can be taken concurrently. Adults should take 0.6-0.8g daily for 2-4 weeks, or ketoconazole 0.2g for 2-4 weeks. Itraconazole or terbinafine can also be considered as appropriate.
3. If accompanied by tinea manuum, tinea pedis, or onychomycosis, simultaneous treatment is necessary.
4. Maintain personal hygiene, avoid using bath basins, slippers, towels, or undergarments of tinea patients, and avoid contact with dogs or cats infected with tinea.

bubble_chart Differentiation

This disease should sometimes be differentiated from erythema annulare, pityriasis rosea, eczema, neurodermatitis, or erythema intertrigo, and fungal examination may aid in the final diagnosis.