The Case

The following pruritic rash is the reason for a visit to the ED. You are aiming to be efficient and nail the diagnosis and present a treatment plan while also presenting three patients with right lower abdominal pain to your attending.

Courtesy NHS.UK Accessed 3/15/23

The Diagnosis

Of course it’s ringworm! Also known as dermatophytosis or tinea corporis, ringworm is a common fungal infection that affects the skin, hair, and nails. It is caused by dermatophytic fungi that loooove warm and humid environments. It is highly contagious and can be spread through direct contact with an infected person or animal, as well as through contact with contaminated objects such as combs, brushes, and clothing. People who are at higher risk of developing ringworm include those who live in crowded or humid environments, those who have weakened immune systems, and those who have a history of skin conditions such as eczema. The most common species include;

  • Trichophyton rubrum
  • Trichophyton tonsurans
  • Microsporum canis
  • Epidermophyton floccosum

It is most common in children and young adults. Symptoms vary depending on the location of the infection.

  • Tinea corporis: Infection of the skin. It usually appears as a red, scaly rash that is circular or ring-shaped, hence the name ringworm. The rash may be itchy and may have raised edges
  • Onychomycosis: When the infection affects the nails, it can cause the nails to become thick, discolored, and brittle.
  • Tinea capitis: Infection of the scalp, it can cause patchy hair loss and scaly, red areas on the scalp.
  • Tinea cruris: Jock itch, perineal infection
  • Tinea manuum: hand
  • Tinea pedis: Feet

The diagnosis is usually made based on the appearance of the rash or affected area. Occasionally a fungal culture (or even biopsy) may be necessary to confirm the diagnosis. Ringworm can look a lot like eczema as well (nummular eczema, nummular means coin!).

Management

For mild cases of tinea corporis, over-the-counter antifungal creams, lotions, or powders are often effective. they should be applied as directed for two weeks, even if symptoms get better sooner. These include;

  • clotrimazole
  • miconazole
  • terbinafine
  • tolnaftate

For more severe cases of tinea corporis or for infections that do not respond to topical treatments, oral antifungal medications may be necessary. These include terbinafine, itraconazole, and fluconazole – which are typically taken for two to four weeks, depending on the severity of the infection. Tinea capitis requires oral therapy, generally griseofulvin. Oral antifungals can impact meds for patients with chronic liver or kidney disease.

Counsel patients on prevention which includes maintaining good personal hygiene, avoiding contact with infected people or animals, and avoiding sharing personal items such as combs, brushes, and clothing. It is also important to keep the skin clean and dry, as moist environments can promote the growth of fungi. Wash those horses shoes!

References

Yee G, Al Aboud AM. Tinea Corporis. [Updated 2022 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK544360/

Ringworm. NHS. https://www.nhs.uk/conditions/ringworm/ – Accessed 3/15/2023