Skin Infections

What is ringworm?

Ringworm, also known as dermatophytosis, dermatophyte infection, or tinea, is a fungal infection of the skin.

“Ringworm” is a misnomer, since a fungus, not a worm, causes the infection. The lesion caused by this infection resembles a worm in the shape of a ring — hence the name.

Ringworm is usually specifically used to describe tinea corporis (ringworm of the body), although it can sometimes be used to describe tinea infection in other locations, such as tinea cruris (ringworm of the groin).

Ringworm infection can affect both humans and animals. The infection initially appears as red patches on affected areas of the skin and later may spread to other parts of the body. It may affect the scalp, feet, nails, groin, beard, or other areas.

Recognizing ringworm symptoms

Symptoms vary depending on where you’re infected. With a skin infection, you may experience the following:

• red, itchy, or scaly patches, or raised areas of skin called plaques
• patches that develop blisters or pustules
• patches that may be redder on the outside edges or resemble a ring
• patches with edges that are defined and raised

If you’re experiencing dermatophytosis in your nails, they may become thicker or discolored, or they may begin to crack. This is called dermatophytic onychomycosis, or tinea unguium. If your scalp is affected, the hair around it may break or fall off, and bald patches may develop. The medical term for this is tinea capitis. Find out more about scalp ringworm and its effects.

Causes of ringworm

Three different types of fungi can cause ringworm: Trichophyton, Microsporum, and Epidermophyton. It’s possible that these fungi may live for an extended period as spores in soil. Humans and animals can contract ringworm after direct contact with this soil.

The infection can also spread through contact with infected animals or humans. The infection is commonly spread among children and by sharing items harboring the fungus.

Different types of fungi cause ringworm. Doctors call ringworm different names depending on where it affects the body:

• Ringworm of the scalp (tinea capitis) often starts as isolated scaling in the scalp that develops into itchy, scaly bald patches. It’s most common among children.
• Ringworm of the body (tinea corporis) often appears as patches with the characteristic round ring shape.
• Jock itch (tinea cruris) refers to ringworm infection of the skin around the groin, inner thighs, and buttocks. It’s most common in men and adolescent boys.
• Athlete’s foot (tinea pedis) is the common name for ringworm infection of the foot. It’s frequently seen in people who go barefoot in public places where the infection can spread, such as locker rooms, showers, and swimming pools.
• Getting a ringworm diagnosis

Your doctor will diagnose ringworm by examining your skin and possibly using a black light to view your skin in the affected area. Depending on the type of fungus, it may sometimes fluoresce (glow) under black light.

Your doctor may confirm a suspected diagnosis of ringworm by requesting certain tests:

• If you’re getting either a skin biopsy or fungal culture, your doctor will take a sample of your skin or discharge from a blister and send it to a lab to test it for the presence of fungus.
• If you’re getting a KOH exam, your doctor will scrape off a small area of infected skin onto a slide and place drops of a liquid called potassium hydroxide (KOH) on it. The KOH breaks apart normal skin cells, making the fungal elements easier to see under a microscope.

Ringworm treatment

Your doctor may recommend both medications and lifestyle adjustments to treat ringworm.

Medications

Your doctor may prescribe various medications depending on the severity of your ringworm infection. Jock itch, athlete’s foot, and ringworm of the body can all be treated with topical medications, such as antifungal creams, ointments, gels, or sprays.

Ringworm of the scalp or nails may require prescription-strength oral medications such as griseofulvin (Gris-PEG) or terbinafine.

Over-the-counter (OTC) medications and antifungal skin creams may be recommended for use as well. These products may contain clotrimazole, miconazole, terbinafine, or other related ingredients. Find antifungal treatments online.

Lifestyle adjustments

In addition to prescription and OTC medication, your doctor may recommend that you care for your infection at home by:

• washing bedding and clothes daily during an infection to help disinfect your surroundings
• drying areas thoroughly after bathing
• wearing loose clothing in affected areas
• treating all infected areas (not treating tinea pedis can lead to recurrence of tinea cruris)

What Is a Staph Infection of the Skin?

A staph infection is caused by a Staphylococcus (or "staph") bacteria. Actually, about 25% of people normally carry staph in the nose, mouth, genitals, or anal area, and don’t have symptoms of an infection. The foot is also very prone to picking up bacteria from the floor. The infection often begins with a little cut, which gets infected with bacteria. This can look like honey-yellow crusting on the skin.

These staph infections range from a simple boil to antibiotic-resistant infections to flesh-eating infections. The difference between all these is the strength of the infection, how deep it goes, how fast it spreads, and how treatable it is with antibiotics. The antibiotic-resistant infections are more common in North America, because of our overuse of antibiotics.

One type of staph infection that involves skin is called cellulitis and affects the skin's deeper layers. It is treatable with antibiotics.

This type of infection is very common in the general population -- and more common and more severe in people with weak immune systems. People who have diabetes or weakened immunity are particularly prone to developing cellulitis.

What Are the Symptoms of a Staph Infection of the Skin?

Staph cellulitis usually begins as a small area of tenderness, swelling, and redness. Sometimes it begins with an open sore. Other times, there is no obvious break in the skin at all.

The signs of cellulitis are those of any inflammation -- redness, warmth, swelling, and pain. Any skin sore or ulcer that has these signs may be developing cellulitis. If the staph infection spreads, the person may develop a fever, sometimes with chills and sweats, as well as swelling in the area.

Other staph infections of the skin include impetigo, a painful rash that is contagious, boils, and in babies and young children, staphylococcal scalded skin syndrome, which causes rash, blisters, and fever.

What’s the Treatment for a Staph Infection?

Antibiotics are used to treat staph infections. But there's been a gradual change in how well these antibiotics work. While most staph infections used to be treatable with penicillin, stronger antibiotics are now used.

Impetigo

Impetigo (im-puh-TIE-go) is a common and highly contagious skin infection that mainly affects infants and children. Impetigo usually appears as red sores on the face, especially around a child's nose and mouth, and on hands and feet. The sores burst and develop honey-colored crusts.

Treatment with antibiotics is generally recommended to help prevent the spread of impetigo to others. It's important to keep your child home from school or day care until he or she is no longer contagious — usually 24 hours after you begin antibiotic treatment.

Symptoms

• Bullous impetigo
• Ecthyma

Classic signs and symptoms of impetigo involve red sores that quickly rupture, ooze for a few days and then form a yellowish-brown crust. The sores usually occur around the nose and mouth but can be spread to other areas of the body by fingers, clothing and towels. Itching and soreness are generally mild.

A less common form of the disorder, called bullous impetigo, may feature larger blisters that occur on the trunk of infants and young children.

A more serious form of impetigo, called ecthyma, penetrates deeper into the skin — causing painful fluid- or pus-filled sores that turn into deep ulcers.

When to see a doctor

If you suspect that you or your child has impetigo, consult your family doctor, your child's pediatrician or a dermatologist.

Causes

You're exposed to the bacteria that cause impetigo when you come into contact with the sores of someone who's infected or with items they've touched — such as clothing, bed linen, towels and even toys.

Risk factors

Factors that increase the risk of impetigo include:

• Age. Impetigo most commonly occurs in children ages 2 to 5.
• Crowded conditions. Impetigo spreads easily in schools and child care settings.
• Warm, humid weather. Impetigo infections are more common in summer.
• Certain sports. Participation in sports that involve skin-to-skin contact, such as football or wrestling, increases your risk of developing impetigo.
• Broken skin. The bacteria that cause impetigo often enter your skin through a small skin injury, insect bite or rash.

Adults and people with diabetes or a weakened immune system are more likely to develop ecthyma.

Complications

Impetigo typically isn't dangerous. And the sores in mild forms of the infection generally heal without scarring.

Rarely, complications of impetigo include:

• Cellulitis. This potentially serious infection affects the tissues underlying your skin and eventually may spread to your lymph nodes and bloodstream. Untreated cellulitis can quickly become life-threatening.
• Kidney problems. One of the types of bacteria that cause impetigo can also damage your kidneys.
• Scarring. The ulcers associated with ecthyma can leave scars.

Prevention

Keeping skin clean is the best way to keep it healthy. It's important to wash cuts, scrapes, insect bites and other wounds right away.

To help prevent impetigo from spreading to others:

• Gently wash the affected areas with mild soap and running water and then cover lightly with gauze.
• Wash an infected person's clothes, linens and towels every day and don't share them with anyone else in your family.
• Wear gloves when applying antibiotic ointment and wash your hands thoroughly afterward.
• Cut an infected child's nails short to prevent damage from scratching.
• Wash hands frequently.
• Keep your child home until your doctor says he or she isn't contagious.
• Treatment

Impetigo typically is treated with an antibiotic ointment or cream that you apply directly to the sores. You may need to first soak the affected area in warm water or use wet compresses to help remove the scabs so the antibiotic can penetrate the skin.

If you have more than just a few impetigo sores, your doctor might recommend antibiotic drugs that can be taken by mouth. Be sure to finish the entire course of medication even if the sores are healed. This helps prevent the infection from recurring and makes antibiotic resistance less likely.