Superficial Mycoses (Fungal infection of Skin, Hair and Nails)

 

Superficial Mycoses

Superficial mycoses are fungal infections mainly caused by dermatophytes (a group of filamentous fungi) that possess the enzymes to break down keratin (the protein) found in the outer layers of the skin, hair, and nails. These fungi grow vigorously in warm, moist environments and are capable of colonizing human hosts, leading to various clinical appearances. This fungal infection spread to human by direct contact from other infected human, animals or from the soil.

Dermatophytes

The most common Genera of dermatophytes involved in causing superficial mycoses are:

·    Trichophyton

·    Microsporum

·    Epidermophyton

These are the genera of fungi showing specific reaction at different areas of the body with clear-cut clinically visible symptoms. 

The kind of infections above mentioned fungi causes are:

1.   Tinea corporis: This infection, typically presents as annular (ring like), erythematous (red inflamed) lesions with raised borders and central clearing commonly known as Ringworm. It can affect any part of the body surface, except the scalp, palms, and soles. But most commonly its growth observed at arms, legs, neck and trunk areas. The infection spreads with growth of hyphae into keratinized tissues, leading to the characteristic appearance.

The treatment involves over the counter antifungal ointments such as clotrimazole, ketoconazole etc. uncontrolled infections may need to take oral (by mouth) medicines.  

2.  Tinea pedis: Also referred to as athlete's foot, this superficial mycosis primarily affects the spaces in-between the fingers of the toes and under-surfaces of the feet. It gives itch, shows erythematous, scaly lesions with fissuring (fine cracks) and maceration (soft and soaked skin), often came with a foul odor. The warm, moist environment within footwear helps fungal growth and colonization. The infection commonly spread through swimming pools, public bathrooms, showers, bathtubs and infected nail cutters. To avoid the infections, keep feet dry and clean.

Infected skin can be treated with medicated ointments such as terbinafine, clotrimazole and luliconazole.

3.    Tinea cruris: Commonly known as jock itch (jock means athlete), this dermatophyte infection predominantly affects the inguinal (near the groin) and perineal (between the anus and the genital organs) regions, as well as the inner thighs. This infection affects hair and epidermis (top layer on the skin) and is transmitted by humans, animals, soil and autoinfection from one area of the body is also possible. Sports persons or family members sharing towels and cloths may transmit the infection to each other. The symptoms involve as intense itch, presents as well-demarcated, erythematous with peripheral scaling and central clearing more prominent in individuals with increased sweating.

Treatment involved use of terbinafine, butenafine, clotrimazole or ketoconazole ointments twice a day for four weeks. The prolonged infection may need oral medications such as terbinafine, itraconazole or fluconazole after consulting the healthcare provider.

4.   Tinea capitis: This superficial mycosis affects the scalp and hair follicles, primarily in children but occasionally in adults. Clinical manifestations vary and may include scaling, erythema, alopecia (baldness), and follicular blisters. Different dermatophyte species exhibit varying degrees of invasiveness, with some causing non-inflammatory scaling (e.g., Trichophyton tonsurans) and others leading to inflammatory or fluid/pus accumulation (e.g., Microsporum canis). The infection transmitted from barber shop, shared brushes, combs, hair equipment, pillows, beddings and towels.

Treatment involved use of terbinafine, butenafine or itraconazole ointments may need oral medications. If its in the family, then treatment of whole family is required otherwise the infection kept shifting from one person to the other.

5.    Tinea versicolor: Caused by yeast Malassezia spp., this superficial fungal infection results in hypo- or hyperpigmented spots on the trunk, neck, chest, arms and rarely on face. The light and dark patches can be of different colour like red, white or brown. The yeast disrupts normal melanin production and distribution, leading to the characteristic dyschromic patches. Factors such as heat, humidity oily skin, weak immune system and hormonal changes increases the growth and clinical expression of the infection.

Treatment involved use of clotrimazole, ketoconazole or terbinafine ointments