Ringworm

Dear Lisa,

My friend’s son had a rash that they thought was Eczema. His mother brought him to the Doctor’s office and it turned out that he has Ringworm. My 7 year old son was playing with him the other day. Does this mean that my son is going to get Ringworm too? What is Ringworm? Does it mean that there is a worm under the skin?

“What is Ringworm?’

Dear “What is Ringworm?”,

Ringworm or Tinea Corporis is a common fungal skin infection found in children. It is called Ringworm because the lesion on the skin is in the shape of a circle or ring, not because there is a worm under the skin. (1) The rash typically appears as flat, round, pink lesions with a distinct scaly border but may also appear as inflammed nodules. (2) If you feel a Ringworm lesion it has a rough texture and in some people it may appear the same color as their skin. If left untreated the lesion enlarges and tends to have central healing or an area in the middle that appears less scaly. (3)

The skin lesions are typicaly found on the non-hairy parts of the body such as the face, body and extremities. (1) Tinea rashes found on hairy parts of the body have different names and courses of treatment. Ringworm on the scalp is called Tinea Capitis and is much harder to treat than Tinea Corporis(Ringworm on the body).

The microorganisms Trichophyton tonsurans and Microsporum canis are the most common causes of Ringworm. (2) Microsporum canis is responsible for the majority of the cases of ringworm in the United States and Europe. (4) Cats and dogs are natural reservoirs of Microsporum canis and they typically do not show signs of the infection. (2) Other animal hosts include cattle, sheep, pigs, rodents and monkeys.

The organism is transmitted when an exposed area of the child’s skin comes into direct contact with an infected animal or its dander. (2) The condition can also be spread due to direct contact with an infected child’s lesions, clothing or towels.

Usually Ringworm is diagnosed by a Doctor or Nurse Practitioner through a physical examination of the child. Sometimes the symptoms mimic the appearance of Eczema or in other instances the characteristics of the lesion may be altered due to the application of steroid crème.

When this occurs, a Wood’s lamp examination could be performed in the Doctor’s office in order to aide in the diagnosis. A Wood’s lamp is an Ultraviolet lamp which is used in a darkened room to identify fungal infections. When the skin is exposed to this light it will fluoresce if a fungal infection is present. A greenish glow should appear at the site of the lesion if the rash is due to Ringworm. (2, 3)

Some Doctor’s may take a scraping of the lesion and look at the cells under a microscope in order to make a diagnosis. A culture of the site may also be obtained, but the results typically are not available for weeks. (2) Therefore this approach is usually reserved for children with persistent conditions or for children with lesions on the scalp.

In regards to the question about your son catching Ringworm from his friend, if he had direct skin contact with his friend’s lesions there is a chance that he will catch it. If he shared towels or clothes with his friend he also is at risk. The exact incubation period for Ringworm is not known; therefore it would be a good idea to inspect your son's skin over the next few weeks. If your child develops a new skin lesion he should be evaluated by his Pediatrician in order to confirm the diagnosis.

If your son develops Ringworm, it can be easily remedied with the use of topical antifungal crèmes such as clotrimazole, miconazole or ketoconazole applied twice per day. (2) Ringworm is not the type of skin infection that dissapears after a couple of applications of medicated crème. Unfortunately, it takes a much longer time to go away. Typically the treatment needs to be continued for 4 to 6 weeks before resolution occurs. (1)

I found that many times a child’s Ringworm reoccurs because the treatment is discontinued too soon. When the lesion is initially treated it tends to lighten in color and this may be interpreted as the resolution of the problem. The fungal infection remains on the skin and may be difficult to see at this point, but can still be felt. I recommend that parents continue treatment until they can no longer feel the lesion.


It is a good idea to cover the lesions with a band-aide when the child is outdoors or around other children in order to limit the spread of the infection. A band-aide also prevents the child from scratching the area. Whenever there is a break in the skin integrity or a rash present that causes a child to scratch, superinfection with a bacteria may occur. Signs of a bacterial skin infection include fever, pain, warmth or redness of the skin, induration (hardening) of the skin, streaking, discharge or odor. (5)

If signs of a bacterial infection occur contact your child’s pediatrician for an evaluation. In addition, if the Ringworm lesion persists, become recurrent, enlarges or travels to the scalp it is important to have your child evaluated by a healthcare professional.


References:
(1)American Academy of Pediatrics. Tinea Corporis. In: Peter G, ed. 1997. Red Book: Report of the Committee on Infectious Disease. 24th ed. Elk Grove Village, IL: American Academy of Pediatrics; 1997:525-526.
(2)Ringworm. Consultant for Pediatricians. 2006. January:44.
(3)Chow M, Durand B, Feldman M, Mills M. Handbook of Pediatric Primary Care. Albany, New York:Delmar Publishers Inc. 1984:604-622.
(4)Chan YC, Friedlander SF. New Treatments for tinea capitis. Curr Opin Infect Dis. 2004:17:97-103.
(5)Graham M, Uphold C. Clinical Guidelines in Child Health. Gainsville, Florida: Barmarrae Books. 1994:231-233.

Lisa-ann Kelly R.N., P.N.P.,C.
Certified Pediatric Nurse Practitioner

Pediatric Advice About Preventing Childhood Infections