Ringworm (Tinea) is a contagious infection of the superficial layer of the skin caused by a fungus. Common fungus that cause ringworm are Trichophyton and Microsporum species. The name ringworm comes from the appearance of the lesion which is a red, advancing circular lesion with clearer skin in the center. The lesions are usually itchy. It is not related to hookworm or roundworm infection.

Types

Depending on the part of the body affected it may be divided into the following groups:

• Tinea pedis – fungal infection of the feet; also known as athlete’s foot
• Tinea unguium (onychomycosis) – fungal infection of the toenail and fingernail
• Tinea corporis – fungal infection of the skin mainly involves trunk, leg and arms
• Tinea cruris– fungal infection of the groin and adjacent skin
• Tinea manuum – fungal infection of the hands and feet; sometimes referred as two feet – one hand syndrome (typically the hand used to scratch the foot with the rash is affected)
• Tinea capitis – fungal infection of the scalp and hair
• Tinea barbae – fungal infestation of facial hair

Causes

Warm, moist areas are favorable conditions for the growth of fungi, so those living in a warm, humid climate are at greater risk and areas such as communal showers and locker rooms are areas in which transmission is favorable. The risk increases in those having a poor immune system (such as from HIV/AIDS, cancer, chemotherapy, diabetes, or certain medications) and in athletes involved in contact sports, such as wrestling. Sweating in tight clothing provides a favourable environment for the fungal growth.

Ringworm spreads through contact. Here are a few possible contact options:

• Human to human contact: by direct contact with the lesions of an infected person.
• Animal to human: by touching an animal with ringworm. Ringworm can spread while petting or grooming dogs or cats.
• Soil to human: The spores may also be present in the soil and may infect susceptible persons or animals.
• Objects to human: It is also spread through sharing bedding, towels, shaving instruments, manicure instruments or clothing.

Symptoms

Symptoms depend upon the area affected. The affected skin would have itchy pink rash, scales and crust and the border may be covered with blisters. If the scalp is affected, there would be round patches of hair loss, area of scalp with very brittle hair which is easily pulled out and underlying skin looks pink and swollen along with dry crusty scalp look like dandruff. Similarly if the foot is infected, there would be itchy, burning red scaly cracked skin between the toes which may have unpleasant odor. Whereas fungal infection of the toe and fingernails shows whitish, brownish and yellowish discoloration of the corner of the nail and nail plate which eventually spreads and causes splitting of the nails or even the nail plate will separate from the nail bed.

Diagnosis

Diagnosis is usually made by clinical examination. Fungal materials can be demonstrated on microscopic examination of skin scales treated with 10% potassium hydroxide (KOH) and sometime the fungal culture can be done from the macerated skin but often is not required.

Treatment

• If the superficial skin is affected, apply the antifungal cream or lotion which you can buy in a drugstore (pharmacy); try to keep the area clean and dry and you can also apply the dusting powder to promote dryness of the skin.
• If the scalp is affected; use shampoo containing selenium sulfide (1%-2.5%), zinc pyrithione (1%-2%), or ketoconazole.
• Sometime systemic antifungal medications needed to treat the infection. The common antifungal medications are fluconazole, Miconazole, Itraconazole, Terbinafine and Griseofulvin.
• Bacterial superinfections usually require systemic antibiotics
• Seriously infected or deep abscesses may require surgical drainage.

When to seek a Doctor?

• If the ringworm lesions do not subside after a week applying over-the-counter antifungal cream, lotion or powder, you need to go to a doctor. As the ringworm might look similar to other skin conditions like eczema or psoriasis, it is important to have a physician diagnose this condition to treat it properly.
• If you develop fever, increased pain, swelling, drainage, or redness, which could suggest a secondary bacterial infection of the ringworm lesion, go to a hospital immediately.

Prevention

• Ringworm is highly contagious; try to avoid contact with personal items of infected persons like clothing, towels, bedding, hair care items and wash the linens and clothes of an infected family members separately.
• Avoid infected animals
• Wear loose fitting cotton undergarments, keep the groin area dry and clean
• Try to avoid tight fitted shoes; dry the toes after taking a shower, change shocks frequently