Ringworm
Ringworm, also known as tinea corporis, is a common fungal skin infection caused by dermatophytes, such as Trichophyton rubrum, which typically leads to itching, scaling, and sometimes painful lesions on the skin. Despite its name, ringworm is not caused by a worm; rather, it is characterized by round lesions that may appear red with scaly borders and normal skin in the center. The infection can affect areas of the body, particularly where the skin is exposed, such as the face and arms. Ringworm is contagious, easily spreading from person to person, and can also be transmitted through animals, especially pets like cats and dogs.
Diagnosis is usually made through examination of skin lesions, and in some cases, skin scrapings or cultures are used to confirm the presence of the fungus. Treatment typically involves antifungal creams that can be applied directly to the affected area, with oral medications available for more severe cases. Prevention includes maintaining cleanliness, keeping the skin dry, and avoiding contact with infected individuals or animals. If you are experiencing symptoms consistent with ringworm, consulting a healthcare provider for diagnosis and appropriate treatment options is advisable.
Ringworm
ALSO KNOWN AS: Tinea corporis
ANATOMY OR SYSTEM AFFECTED: Skin
DEFINITION: A group of fungal diseases caused by several species of dermatophytes and characterized by itching, scaling, and sometimes painful lesions
CAUSES: Fungal infection
SYMPTOMS: Itching, scaling, sometimes painful lesions
DURATION: Approximately one month
TREATMENTS: Topical skin creams, antifungal medications
Causes and Symptoms
Ringworm is a fungal skin infection characterized by itching and redness. Despite its name, it is not caused by a worm; instead, it is an infection caused by dermatophytes such as Trichophyton rubrum, Microsporum rubrum, Epidermophyton rubrum, and Trichophyton rubrum. The skin in areas affected with ringworm often contains round lesions that are colored red, have scaly borders, and contain normal-appearing skin in their centers. Alternatively, the lesions can simply be scaly, red patches with no clearly defined shape. Typically, these lesions are relatively small, approximately 1 inch in their largest dimension. Complications of ringworm include spread to the scalp, hair, or nails of the fingers or toes. The fungus uses the protein keratin as a nutritional source. Ringworm belongs to a group of skin infections called tinea, which also includes athlete's foot and jock itch.
The lesions of ringworm are most commonly caused by Trichophyton rubrum. Ringworm appears on exposed areas of the body, often on the face and arms. Ringworm is contagious and spreads from person to person, but animals, particularly pets such as cats and dogs, can also carry and transmit the infection.
Examination of skin lesions is used to diagnose ringworm. However, sometimes scrapings are used to confirm the diagnosis. Species of fungus can be tentatively identified by their microscopic structure. Culturing material from a skin lesion provides a definitive diagnosis.
Treatment and Therapy
The treatment of ringworm involves antifungal creams that are applied to the skin and are available without a prescription. These topical antifungals should be applied once or twice daily to the lesions and two centimeters of the normal skin around the lesions. Antifungals should be continued for one to two weeks after the skin lesions have cleared. Oral antifungals are available but require a physician’s prescription. They are used for more extensive lesions, when fingernails or toenails are involved, or if the infection is unresponsive to topical treatment. Body ringworm usually responds within four weeks of treatment. Avoiding contact with infected household pets or clothing that has been worn by an infected person can prevent ringworm. The affected area should also be kept clean and dry.
Perspective and Prospects
Tinea can cause infections in other parts of the body: tinea capitis on the scalp, tinea pedis on the feet, and tinea cruris in the groin region. Ringworm must be differentiated from several other diseases that also cause skin lesions: tinea versicolor, psoriasis, syphilis, pityriasis rosea, and discoid lupus erythematosus. The lesions of psoriasis usually appear on the elbow, knees, and scalp. Syphilis lesions usually appear on the mucous membranes of the genitals or on the palms of the hands or soles of the feet. Although pityriasis rosea often begins with a single round lesion, many more usually follow. The classic skin lesion of lupus is butterfly-shaped and covers the nose and cheeks. The presence of a cat or other domestic pet is often an important element in establishing a diagnosis of ringworm.
Bibliography
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Ely, John W., Sandra Rosenfeld, and Mary Seabury Stone. "Diagnosis and Management of Tinea Infections." American Family Physician 90.10 (2014): 702–11. Web. 2 May 2016.
Habif, Thomas P. Clinical Dermatology: A Color Guide to Diagnosis and Therapy. 6th ed. Philadelphia: Saunders, 2016. Print.
McCarthy, Claire. "Ringworm: What to Know and Do." Harvard Health Publishing, 21 June 2023, www.health.harvard.edu/blog/ringworm-what-to-know-and-do-202306212942. Accessed 8 Apr. 2024.
Patterson, James W. Weedon's Skin Pathology.4th ed. New York: Churchill Livingstone, 2015. Print.
"Ringworm of the Body." MedlinePlus, 18 Nov. 2022, medlineplus.gov/ency/article/000877.htm. Accessed 8 Apr. 2024.