Fungal infections of the skin and nails: not everything that itches is a fungus

In my practice I very often hear: "Doctor, my skin itches", "I have a spot", "I think it's a fungus". Not everything that itches or discolors the skin is a fungus. Many patients come in after using supermarket creams or whatever a neighbor or pharmacy employee recommended. That can hide the real condition or make it worse.

There are many types of fungi and they show up differently depending on the area affected. They usually cause itching, red patches or patches with fine flaking.

1. In skin folds: under the breasts, groin and armpits

It starts with itching and then a red patch appears which, over time, spreads along the fold. It is more common in:

• Athletes who do not shower and change soon after exercise and leave sweat on their skin for a long time.
• People with diabetes or prediabetes.
• People who are overweight.

2. On the arms, legs, face and scalp (ringworm)

It is common in children and teenagers who have dogs or cats. Round patches appear that grow at the edges and, on the scalp, can cause patchy hair loss. It can spread to classmates and family. See pediatric dermatology.

3. On the back and chest: pityriasis versicolor

Light or dark patches with fine flaking appear on the back and can spread to the chest, neck and face. It is more common in people who sweat a lot and in hot, humid climates like ours. It tends to come back, so preventive treatment is sometimes recommended.

4. Athlete's foot

The fungus grows in the moisture and sweat left in sneakers or in closed or rubber shoes that make the feet sweat a lot. It causes itching, flaking and cracks between the toes, and a bad smell.

5. In the nails (onychomycosis)

The nails thicken, turn yellowish or whitish and lift off. Many cases are linked to manicures or pedicures done with poorly sterilized instruments: cleaning them only with alcohol or ordinary disinfectants does not kill the fungi.

Before treatment, a lab test is done to identify the type of fungus. Depending on the result and the number of nails affected, oral or topical medicines are prescribed. Nail treatment is long and requires consistency. Laser has limited results and does not replace medical treatment.

How is it diagnosed?

The dermatologist examines the skin and, when needed, takes a sample of skin scales or nail to look at under the microscope or to culture. This confirms whether it is a fungus, what type it is and what the right treatment is: creams, soaps or oral medicines.

How to prevent fungal infections

• Dry yourself well after bathing, especially in skin folds and between your toes.
• Shower and change your clothes soon after exercising.
• Alternate your shoes and let them dry; wear cotton socks.
• Wear sandals in public showers and locker rooms.
• Bring your own manicure instruments or make sure they are properly sterilized.
• Take your pet to the vet if it has hairless patches.