Ringworm or Tinea

The Fungus Amungus 

          Ringworm or Tinea (a Latin word meaning a growing worm) is one of the most common skin diseases of man.  It is actually caused by a fungus of the dermatophyte (a Greek word meaning skin plant) group, usually of the genus Trichophyton, Epidermophyton or Microsporum.  These fungi have the ability to infect and flourish on the dead keratin that is found in the top layer of skin, hair or nails.  All forms of Tinea (pronounced tih-nee-uh) are contagious and can spread from one infected area of your body to another or can be transmitted through person to person contact or by contact with soil, cats or dogs.  Tinea occurs worldwide in all age groups, but is particularly common in children.  Next to acne, Tinea is the most common skin disease reported in the United States and it is estimated that there is a 10 to 20% chance that each human will acquire a Tinea skin infection sometime during their lifetime.  Areas of the body characterized by moisture, friction and warmth are particularly susceptible, making obesity a predisposing factor. 

Symptoms and Diagnosis 

          Because some forms of Tinea are manifested by a circular lesion with central clearing surrounded by a well-demarcated, advancing, red, scaly, elevated border it has come to be known as ‘ringworm’, although it is not caused by a worm at all.  While the various forms of Tinea generally cause superficial skin infections which are itchy, the appearance and symptoms depend on the site of infection.  Your health care provider can identify the typical branching filaments or hyphae of Tinea by taking a scraping of the skin lesion and looking at a potassium hydroxide wet mount under the microscope.  For recalcitrant infections and infections requiring oral medications a culture is often taken, as well, to confirm the diagnosis.

A Lesson in Anatomy (and Latin!) 

          The appearance, symptoms and treatment of Tinea vary depending on the area of the body that is infected, with the various forms named for the body part involved: 

Tinea Capitis (from the Latin caput meaning head)

          This infection can appear in several different forms on the scalp, from a dandruff-like lesion to a boggy mass known as a Kerion.  It can cause mild to extensive hair loss and may be transmitted by sharing hair combs and brushes.  In addition to microscopic examination and culture it may also be identified by Wood light examination.  Treatment is with oral antifungal medication and patients must take pills for 4 to 6 weeks under the close supervision of a health care provider. 

Tinea Corporis (from the Latin corpus meaning body)

          This form is manifested by the classic circular lesion on the face, trunk or limbs.  It often responds to topical application of antifungal medications, but extensive cases may require oral medications.  Tinea gladiatorum is an interesting form of this infection seen in wrestlers, where skin to skin contact is extensive. 

Tinea Cruris (from the Latin crus meaning leg) Jock Itch

          One of the most common forms of Tinea, it occurs in the groin area and upper thighs.  The margins of the lesion are sharp and generally symmetrical on both sides.  It occurs most often in adolescent and adult males and can be extremely itchy.  It often occurs in association with Tinea pedis (athlete’s foot) and can usually be treated with topical medications.  Keeping the area dry and wearing loose fitting underwear is also important. 

Tinea Manuum (from the Latin manus meaning hand)

          In this form of Tinea one or both hands are infected, causing areas of peeling, dryness and itching, generally on the palms.  It is often seen in association with Tinea pedis.  It can usually be resolved by application of topical antifungal agents. 

Tinea Pedis (from the Latin ped meaning foot) Athlete’s Foot

          Probably the most common of the dermatophyte infections, this form occurs most commonly in men age 20 to 40 years.  It is characterized by a whitish, macerated area between the toes and occasionally on the sides and top of the foot which can be extremely itchy.  It is usually acquired by walking barefoot where someone else with athlete’s foot has walked.  Occlusive footwear and frequent use of gyms, locker rooms and pools are predisposing factors.  Topical antifungal agents are usually effective, but recurrent cases sometimes require oral medications. 

Tinea Unguium (from the Latin unguis meaning nail)

          Tinea is only one type of infection that can involve the nails, usually the toe nails.  It occurs in adults more often than children.  Several factors, including age, diabetes, poor circulation, poorly fitting footwear and sports participation increase one’s chance of acquiring this infection.  The nail becomes brittle, thickened and discolored and is often painful.  Successful treatment generally requires oral antifungal medications. 

Treatment and Prevention 

          Most forms of Tinea can be treated with topical antifungal agents with the notable exceptions of Tinea capitis and Tinea unguium which usually require oral medications.  Treatment can take up to 4 to 6 weeks and sometimes longer.  Sometimes a topical corticosteroid is used together with an antifungal agent to reduce inflammation; however, steroids should never be used alone, as they may make the fungal infection worse.  Because all forms of Tinea are contagious and are acquired by direct contact, there are several steps that can be taken to help prevent infection.  Sharing combs, hair brushes, head gear, towels, and clothing should be avoided.  Wearing flip-flops in the locker room and drying the feet thoroughly after showering can help prevent athlete’s foot.  Because the fungi causing Tinea thrive in warm, moist areas, it is important to keep parts of the body where skin comes into contact with skin dry, such as the groin, under arms, and under the breasts.  It may also help to wear loose fitting clothing and to wash sheets and bed clothing on a daily basis until the infection is resolved.  Tinea can be confused with other skin diseases, including intertrigo, seborrheic dermatitis, psoriasis, irritant and allergic dermatitis and superficial bacterial infections.  Your health care provider can distinguish between the various skin rashes caused by these entities and prescribe the correct treatment for you.