Ringworm

Ringworm is a fungal skin infection that commonly occurs in people irrespective of the age and gender. It is caused by the dermatophyte fungus. The infection spreads from an infected person through a direct skin contact or indirectly by sharing towels, hairbrushes, shoes, and clothes. It can also spread from an infected pet. Tinea or ringworm commonly occurs in the skin areas that remain moist and do not dry easily such as the skin folds in the groin region, in between the toes, scalp, hands, and beard. According to the World Health Organization (WHO), the worldwide prevalence of fungal skin infection varies between 20-25%, and it is commonly seen in countries with warm and moist climate like India. In India, a majority of fungal skin infection cases are caused by the dermatophyte fungus. Mostly, the infection occurs on the body, the groin region, nails, and the scalp. 

Ringworm can develop on any part of the body. However, the distinct ring-shaped pattern is absent in a nail infection. Depending upon the area involved, ringworm can be of the following types:

• Tinea corporis is a general term used for a ringworm occurring anywhere on the body.
• Tinea cruris, also known as jock itch, is ringworm in the groin region.
• Tinea pedis or athlete’s foot is a term used to denote ringworm on the soles, especially between the toes.
• Tinea unguium or onychomycosis denotes ringworm affecting the nails.
• Tinea manuum is a fungal infection of the palms.
• Tinea capitis is used to define ringworm on the scalp.
• Tinea barbae denotes ringworm of the beard, which affects the skin over the chin and jawline.
• Tinea faciei denotes ringworm on the face in areas other than that of the beard.

It is essential to treat ringworm irrespective of the area involved in order to prevent the spread of infection to other parts of the body and to other individuals.

A typical ringworm lesion comprises of a skin rash or eruptions in the shape of a circle or a ring. The edges of the lesion are raised and red in appearance and consist of silvery scales. The central portion of the circular lesion tends to remain clear and unaffected. There is intense itching in the infected skin patch, which grows in size and number in the absence of treatment. Besides the typical skin rash, ringworm in different skin areas gives rise to different signs and symptoms as explained below:

Tinea corporis or ringworm on any part of the body

• A round patch with a raised border and a clear area in the centre.
• The patch may appear red, pink, grey or brown.
• Multiple ring-shaped patches may fuse together and spread to a larger area.
• Sometimes, pus-filled boils may also appear around the rash.

Tinea cruris or ringworm in the groin (jock itch)

• Swelling and redness in the groin region are present in the initial stages of infection.
• The rash gradually increases in size and extends to the inner thighs, waist, and buttocks.
• The involved skin develops scales, which may peel off or develop cracks.
• The border of the circular patch of infection is raised and may have pus-filled boils.
• Severe itching is frequently present with the infection.

Tinea pedis or ringworm on the soles (athlete’s foot)

• The skin on the soles and between the toes is dry with scales peeling off easily.
• The dry skin develops cracks that tend to bleed.
• The infection spreads to the other parts of the feet and develops a rash with pus-filled boils along with intense itching and pain.
• The skin between the toes becomes white, soft, and spongy.
• Due to severe infection, the involved skin on the feet, especially between the toes has an unpleasant smell.

Tinea unguium or ringworm on the nails

• Single or multiple nails may be involved.
• Swelling and redness in the nail bed are seen in the initial stages of infection.
• The colour of the nails changes to black, yellow or green.
• Nails become thick, brittle and get detached from the nail bed as the infection progresses further.
• Commonly seen in people suffering from athlete’s foot.

Tinea capitis or ringworm on the scalp

• The scalp develops patches of crust.
• The hair falls off leaving behind a bald patch.
• Black spots are seen in the bald patches.
• The affected skin on the scalp is red and swollen due to inflammation.
• Severe itching in the scalp is also experienced commonly.

Tinea barbae or ringworm in the beard

• Ringworm develops on the skin in the beard and moustache region, which has thick hair growth.
• The skin becomes red, swollen, and discharges a transparent fluid.
• The affected skin may also consist of pus-filled boils.
• The hair in the affected area falls off due to damaged hair follicles.
• There is severe itching in the infected skin.

Tinea manuum or ringworm on the hands

• The skin on the palms becomes very dry with cracks in between.
• The ring-shaped patch of infection is usually seen on the back of the hand.

Tinea faciei or ringworm on the face.

• The skin on the face (other than the beard area) is red.
• There is severe itching and burning on the face, especially when exposed to the sun.
• The infected skin may or may not show the typical ring-shaped pattern of the rash.

Causes

Ringworm or tinea is caused by a fungus called dermatophyte, which feeds on keratin, a protein found in abundance in the skin, nails and hair. Hence, these are the most commonly infected body parts.

Modes of transmission

The dermatophyte fungus survives on the skin or other infected surfaces for a long time and spreads easily in the environment through various modes of transmission, such as:

• From an infected person
  The fungus spreads by a direct contact with an infected person. The infection may also spread indirectly by sharing items, such as clothes, towels, hairbrush, and other personal belongings with an infected person.
• From animals
  Pets and other domestic animals, such as dogs, cats, cows, goats, pigs, and horses commonly have ringworm. Thus, it may spread to healthy people through a close contact with these animals.
• From soil and infected surfaces
  The fungus can survive for a long time in warm and moist surfaces such as soil, damp rooms, and swimming pools thus causing people to get easily infected with it.

Risk factors

Ringworm affects people of all age groups. However, the risk of developing infection is more in the following cases:

• Individuals with a weak immune system due to various reasons (chemotherapy, corticosteroid medications, HIV infection, diabetes among others) are at a high risk of developing ringworm. The severity of ringworm is high in people infected with HIV.
• Children are at a high risk of developing tinea infection in the scalp.
• Obesity increases the risk of developing ringworm as the fungi tend to grow easily in the skin folds.
• People involved in sports such as wrestling, football, swimming and basketball are at a higher risk of developing ringworm due to excessive sweating, damp areas (swimming pools) and a close contact with other participants while playing. Sportspeople frequently suffer from jock itch and athlete’s foot.
• People who sweat excessively and wear tight shoes or clothes have a tendency to get tinea easily.
• Those who have pets in their homes are more prone to developing ringworm. Farmers are prone to fungal infection due to long exposure to the soil and farm animals.
• People living in dormitories or military camps or housings are likely to develop ringworm due to a close contact with other people and sharing personal items such as hair brushes, razors, and towels7.
• Walking barefoot in damp rooms or in the soil increases the risk of acquiring ringworm.

Ringworm can be easily prevented by taking certain measures to keep oneself and the surrounding areas dry and clean. These include: 

• Bathing twice a day after exercise and sports activity and during summer season helps to keep the skin clean.
• Keep the skin dry, especially in the skin folds of the toes.
• Wear clean and dry clothes and undergarments.
• Cotton clothes help to absorb sweat and keep the skin dry.
• Using gloves and washing hands and feet with soap after handling ringworm-infected pets helps to prevent its spread.
• Do not handle pets when your immunity is low, such as during an illness or after a chemotherapy.
• Do not share personal items with others, especially with an infected person.
• Avoid using public showers, damp rooms, and locker rooms barefoot.
• Do not wear tight fitting clothes, shoes or socks, especially during the summer season.
• Moderate regular exercise helps to maintain body weight and prevents ringworm infection in the skin folds.
• Controlling the blood sugar levels in diabetes also helps in improving the immunity and preventing infections.
• Clothes and undergarments should be changed every day and washed thoroughly before wearing them again.
• Pets should be treated for ringworm to prevent the spread of infection.
• The areas in the house that are often visited by pets should be cleaned frequently.
• People involved in sports such as wrestling or football where there is close contact with other players while playing should avoid sharing uniforms or helmets with others.

Doctors diagnose ringworm chiefly on the basis of physical examination, history of the clinical symptoms, and very rarely, using lab tests.

Physical examination

While conducting a physical examination, your doctor will look for the following signs and symptoms typical of ringworm, such as:

• The presence of a ring-shaped rash with a raised border and a clear area in the centre is a diagnostic feature of ringworm.
• The affected area looks red with the presence of scales that peel off from the infected skin.
• In some cases, there is a fluid discharge or formation of thick crust on the infected area.
• Intense itching in the affected region is characteristic of a fungal infection.
• Lymph nodes in the neck and back of the head are enlarged and swollen in ringworm of the scalp or beard.

Lab tests

• KOH microscopy
  A small sample of the infected skin or debris scraped from the infected nail is stained with a chemical called potassium hydroxide and observed under a microscope to view the string-like structure of the fungus (fungal hyphae). KOH microscopy is used to confirm the diagnosis of ringworm.
• Wood’s lamp examination
  The ringworm infected skin appears fluorescent when examined under the Wood’s lamp. However, the fluorescence is not visualised in all the cases of ringworm. Hence, the test is not very useful in diagnosing it.
• Fungal culture
  Only rarely, a culture test might be ordered by the doctor to confirm the diagnosis. A small sample of the infected skin or hair is used to grow the fungus on an artificial medium (Sabourand’s medium) in the lab. The test is reported positive after 3 weeks of fungal growth on the medium. A fungal culture is used to confirm the diagnosis, especially in the case of tinea capitis or ringworm of the scalp.

(Consult a doctor with doctor consultation app)

Treatment of ringworm should be started as soon as possible and continued as advised by the doctor in order to prevent the spread and recurrence of the disease. The treatment depends upon the location and severity of the infection. Antifungal medicines stop the growth and multiplication of the fungus and help to cure the infection completely.

Topical antifungal medicines

In the majority of cases, the application of antifungal creams, powders, sprays, or ointments will resolve the infection in 2 to 4 weeks. Common antifungal creams, powders or ointments used for the treatment of ringworm in the feet and groin region contain medicines such as:

• Clotrimazole
• Miconazole
• Terbinafine
• Ketoconazole

The application of nail varnish containing an anti-fungal medicine called ciclopirox is used for the treatment of ringworm of the nails.

Oral antifungal medication

Oral antifungal medicines are necessary for the treatment of ringworm in cases where the infection has spread over a large area of the skin. Ringworm of the scalp does not resolve with the application of antifungal creams or powders. The infection takes 1 to 3 months to resolve completely with the help of oral medicines, such as:

• Griseofulvin
• Terbinafine
• Itraconazole
• Fluconazole

Antifungal shampoos containing selenium sulphide and ketoconazole are used in addition to oral medicines for the rapid cure of ringworm in the scalp.

Lifestyle management

Besides the treatment strategies, ringworm can be managed by modifying your lifestyle. Sticking to healthy habits and maintaining good hygiene in daily life can prevent the spread of ringworm to other body parts or people.

• Clean your hands with soap and water after touching the infected skin to prevent the spread of infection to other body parts.
• Wash the infected area frequently to keep it clean.
• In the case of athlete’s foot, avoid wearing socks or shoes to keep the infected area dry, as warmth and moisture favours the growth and multiplication of the fungus. Also, avoid entering damp rooms, locker rooms, and public showers barefoot and use sandals to prevent the infection from spreading to others.
• Wear clean and dry clothes (especially cotton fabric) and undergarments.
• Do not share your personal belongings with others.
• Exercise regularly and maintain a healthy weight.

Prognosis

Ringworm infection usually gets completely cured without any complications. The prognosis is excellent in most cases. However, ringworm on the hands and nails can take a long time to clear completely. The infection has a tendency to recur in the absence of adequate treatment or in the case of a low immunity. Hence, it is essential to complete the course of medicines in the dosages advised and follow-up with the doctor.

Complications

Complications of ringworm are extremely rare and almost non-existent. However, ringworm may spread rapidly from one part of the body to the other. Sometimes, a bacterial infection may also get superimposed on the damaged skin. In rare cases, ringworm leaves scars and bald patches permanently on the scalp.