What is Jock Itch?
Jock Itch, known medically as Tinea Cruris, is a common fungal skin infection which typically manifests as pruritic skin lesions, affecting the groin region in young adolescents and adults. Epidemiologically, Jock Itch has a global distribution, but is more prevalent in the warm humid climates of tropical regions (Havlickova, Czaika, & Friedrich, 2008).
Socioeconomic status and local cultural practices have significant impacts on the global occurrence of Jock Itch and other dermatophyte infections (Havlickova et al., 2008). Although its prevalence is higher in males, females also get Jock Itch. It is more common in adults as compared to children.
What causes Jock Itch?
Jock Itch is caused by ubiquitous fungal species which have strong predilections for warm, moist body surfaces. Such fungi include T. rubrum, E. Floccosum E.mentagrophytes (Ely, Rosenfeld, & Seabury Stone, 2014).T. rubrum is recognised as the most common causative agent worldwide (Aly, 1994). T. rubrum is the primary fungal species which cause Jock Itch in men, while in women, a mixed fungal flora is frequently observed(Ely, Rosenfeld, & Seabury Stone, 2014).
Is Jock Itch contagious?
Jock Itch is an infectious skin disease that can be transmitted from Person-to-person via the use of contaminated towels, clothes, underwear, and beddings. Based on the observation that close contact during sexual intercourse can be a means of transmission Jock itch is classified as a sexually transmitted disease(STD). Furthermore, occupations such as the military, residence in hostels, or sporting activities which involve shared clothing are particularly important risky settings for transmission. Other risk factors include the use of very tight underwear especially those made of non-absorbent, synthetic fabrics which promote moisture retention in groin area, obesity and diabetes mellitus.
What happens following infection?
Fungi bind to skin cells and commence the expression of a wide range of keratinases: molecules which breakdown inter-cellular junctions on the outer part of the skin (Baldo et al., 2012). The action of skin-resident immune cells may limit initial anchorage to outer skin layer. Acting via the action of pruitogenic neuropeptides which activate pruroceptors located at the dermo-epidermal junction (Metz & Ständer, 2010), fungi induce profound scratching behaviour, leading to a persistence of fungal reservoir underneath the nails, from which long term auto-inoculation may be sustained.
Jock Itch Symptoms and Signs: What does jock itch look like?
The symptoms and signs of jock itch are distinctive. The skin lesions are located in the groin area, but can also be located at skin creases or folds of skin in the obese, beneath the breasts, the axillae (armpits) or in between the buttocks area. Typically,in men, the skin lesions are found between the inner thigh and the scrotum, extending towards the base of the penile shaft, and backwards towards the anus, while the skin over the scrotum is spared.
In women, Jock Itch is restricted to the skin folds between the inner thigh and labia majora. Symptoms of Jock Itch in women are similar to those in men. While the vagina is not affected by Jock Itch, vaginal candidiasis, which also causes remarkable itching may exist concomitantly. There may be simultaneous fungal lesions in other skin sites like the feet ( Tinea pedis).
The skin over the affected area is reddish, moist and sometimes sensitive to touch, with an associated, constant, uncontrollable urge to scratch the groin, which may be a source of social embarrassment.
The affected skin area gives a characteristic offensive odour. Scratching also serves to inoculate the fungi vertically into the inflamed skin as well as well as horizontally over adjacent non-inflamed skin. The primary site may be restricted to one side of the groin, but commonly involves a both groins, from where the disease progresses slowly to involve adjacent skin. However, in people with underlying problems of the immune system who are generally more prone to skin infections, spread may be quite rapid. Following weeks or months of scratching, the skin may appear leathery or shiny (lichenification). If Jock itch is left untreated, long term skin problems such as bumps may result due to super-imposed bacterial infection and scar formation.
How is Jock Itch diagnosed?
Diagnosis is usually made by a combination of visual skin inspection as well as laboratory investigations, which are able to demonstrate the presence of fungi within skin lesions. Skin scrapings can be collected, treated with potassium hydroxide ( KOH) and examined under a microscope, where characteristic fungal forms are visible. Furthermore, skin scrapings can be processed and fungal DNA identified by polymerase chain reaction (PCR).
A unique feature of jock itch is that the lesions always remain locally, and systemic spread to internal organs does not occur. There are other skin conditions which may manifest similar signs and symptoms to Jock Itch. Examples include folliculitis, cutaneous candidiasis, seborrheic dermatitis and intertrigo.
How is Jock Itch treated?
The aims of treatment for Jock Itch include:
- Achieving Complete cure of skin lesions.
- Preventing recurrence.
- Complete cure of Jock Itch.
Elimination of characteristic skin lesions can be achieved by the use of antifungal drugs. These are drugs which act directly on the fungi with minimal effects on human cells. Commonly, they are used topically i.e on the skin at the site of infection. In severe cases, as seen in people with deficient immune functions, they are given either orally (Chang, Young-Xu, Kurth, Orav, & Chan, 2007) .
There are several classes of antifungal drugs currently available for the treatment of Jock Itch. These drugs are formulated as creams, sprays or powders. They include allyamine derivatives, like Butenafine (mentax) and Terbinafine ( Lamisil). Based on current treatment guidelines, Terbinafine and Butenafine are recommended as first line agents in the treatment of Jock Itch. However, as alternatives, ergosterol inhibitors such as Clotrimazole, Miconazole, Ketoconazole, Oxiconazole and Luliconazole may also be used. Many topical antifungal agents are available in pharmacies without the need for doctors’ prescriptions. Topical preparations containing corticosteroids must be avoided as they worsen the spread of the disease.
Complete cure is achieved after treatment duration of 2-6 weeks in over 95% of cases (Moriarty, Hay, & Morris-Jones, 2012). However, treatment may be prolonged in cases where the disease is severe and extensive. During treatment, Jock itch remains contagious and therefore, adequate preventive measures must be sustained during and after treatment.
- Preventing recurrence of Jock Itch.
Following treatment measures aimed at preventing recurrence of Jock Itch include:
- Keeping the groin area dry by the use of powders, especially those with antifungal components.
- Adequate drying of affected area after bathing.
- Avoidance of tight underclothes, especially those made of synthetic fabrics.
- Where possible, clothes or towels must never be shared with others.
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Baldo, A., Monod, M., Mathy, A., Cambier, L., Bagut, E. T., Defaweux, V., . . . Mignon, B. (2012). Mechanisms of skin adherence and invasion by dermatophytes. Mycoses, 55(3), 218-223. doi: 10.1111/j.1439-0507.2011.02081.x
Chang, C.-H., Young-Xu, Y., Kurth, T., Orav, J. E., & Chan, A. K. (2007). The Safety of Oral Antifungal Treatments for Superficial Dermatophytosis and Onychomycosis: A Meta-analysis. The American Journal of Medicine, 120(9), 791-798.e793. doi: http://dx.doi.org/10.1016/j.amjmed.2007.03.021
Ely, J. W., Rosenfeld, S., & Seabury Stone, M. (2014). Diagnosis and management of tinea infections. Am Fam Physician, 90(10), 702-710.
Havlickova, B., Czaika, V. A., & Friedrich, M. (2008). Epidemiological trends in skin mycoses worldwide. Mycoses, 51, 2-15. doi: 10.1111/j.1439-0507.2008.01606.x
Metz, M., & Ständer, S. (2010). Chronic pruritus – pathogenesis, clinical aspects and treatment. Journal of the European Academy of Dermatology and Venereology, 24(11), 1249-1260. doi: 10.1111/j.1468-3083.2010.03850.x
Moriarty, B., Hay, R., & Morris-Jones, R. (2012). The diagnosis and management of tinea (Vol. 345).