What is Tinea Cruris?
Tinea cruris, commonly known as jock itch, is an infection that affects the skin around the genitals, pubic area, area between the anus and genitals (perineal), and the area around the anus (perianal). The infection is caused by certain types of harmful fungi, called dermatophytes, that can impact parts of the skin and hair that contain keratin, a type of protein. Dermatophytes can create a noticeable rash on the skin.
Areas of the body where skin rubs against skin, also known as intertriginous areas, are more prone to these types of fungal infections. Factors like sweating, skin softening (maceration) and alkaline pH levels, which refer to the balance between acidity and alkalinity on skin, can cause the groin area to be particularly susceptible to infection.
Although tinea infections are typically identified by the part of the body that’s affected, they’re also categorized based on how the fungi are primarily spread. There are three types in particular: geophilic, zoophilic, and anthropophilic. These types of fungi are found and spread through soil, animals, and humans, respectively. It’s important to know that these fungi can also spread from one part of the body to another in the same person. This is particularly relevant in the case of jock itch, as the infection can spread from foot to groin.
What Causes Tinea Cruris?
Tinea cruris, often called jock itch, is caused by a type of fungus known as dermatophytes. These dermatophytes belong to three families – Trichophyton, Epidermophyton, and Microsporum. The most common one to cause jock itch is Trichophyton rubrum, but research also shows an increase in instances caused by Trichophyton mentagrophytes and other organisms, particularly in certain parts of the world.
Certain factors can make a person more likely to get jock itch. These include excessive sweating, wearing tight clothing that doesn’t breathe, not washing properly, having diabetes, having a weakened immune system, or being in a lower income bracket.
People who play sports, especially contact sports, may also be at higher risk for jock itch. Your genetic makeup can also make you more likely to get this type of fungus. Of all the factors that contribute to jock itch, sweating seems to be the most influential.
In India, where jock itch seems to be more common and harder to treat, a study was conducted to understand why. The study found that people with diabetes, individuals with family members who had jock itch, and people who cooked meals were all more likely to have recurring and long-lasting jock itch.
Risk Factors and Frequency for Tinea Cruris
Cutaneous mycoses, which include a condition called tinea cruris, impact approximately a quarter of the world’s population. Regions with higher temperatures and humidity, such as developing and tropical countries, often see an increased number of these skin infections. For instance, in the United States, a reported 29.4 million cases of superficial fungal infections have been noted, leading to over 51 million doctor’s visits.
- Adolescent and adult males make up most of the patients with tinea cruris.
- They, in particular, seem to get this disorder more often.
- There is a growing concern worldwide about an increase in these skin infections.
- This is especially true given the discovery of infections that are tough to treat.
Signs and Symptoms of Tinea Cruris
Tinea cruris is a type of skin infection that often results in a rash in the groin area. It can be irritating and even painful, especially if the skin gets excessively wet, or if there are other infections in the same area. Its symptoms can last for different lengths of time, may have happened before, can appear elsewhere on the body, and might have been treated in the past. Certain health conditions, such as diabetes, weakened immune system, kidney disease, or liver problems, can make a person more susceptible to this infection. Other factors like sweaty skin, changes in clothing, personal hygiene habits, or exposure to possibly contaminated soil, animals, or other people assist in its contraction.
During a physical examination, the doctor can usually see a red, scaly, ring-shaped spot that has a prominent border and clear center. This rash might spread from the groin to places like the upper thigh, the region between the thighs, or even the rectal area.
Testing for Tinea Cruris
Tinea cruris, also known as ‘jock itch’, is a type of fungal infection usually diagnosed through a visual inspection by a doctor. However, when the cause of a groin rash is unclear, several tests are available. These include a potassium hydroxide (KOH) preparation test, a skin biopsy with a periodic acid-Schiff (PAS) stain, and fungal cultures on a medium known as Sabouraud’s agar. These tests are especially useful if your doctor isn’t sure about the diagnosis, or if the rash keeps coming back or is hard to treat.
In order to do these tests, a sample is taken from the edge of the rash. The idea is to pick up infected skin flakes for examination. Typically, this is done by using a scalpel to scrape off a bit of skin. But new research suggests that using an adhesive tape method might have some benefits. It may make collecting the sample easier, help with transportation of the sample, get a better quality sample, and keep the sample preserved longer on the slide for analysis.
Treatment Options for Tinea Cruris
Antifungal medications are typically used to treat skin infections caused by fungi, also known as dermatophytoses. These medications work by targeting a crucial part of the fungi’s cell structures, known as ergosterol. Even though treatment processes are generally similar across the world, specific regions may have unique guidelines based on the main types of fungi present in those areas. Medication that is applied directly to the skin, or topical treatment, is usually the preferred choice.
The two main classes of topical medications used are allylamines (e.g., terbinafine, butenafine, naftifine), and azoles (e.g., clotrimazole, miconazole, sulconazole, oxiconazole, econazole, ketoconazole). The choice of medication depends on several factors, such as the patient’s ability to follow the treatment, the cost of the medication, and its accessibility. Allylamines may require a shorter treatment timeframe and have been found to cause fewer relapses, while azoles can be more cost-effective but might require longer use for effective treatment.
Ciclopirox olamine is an older topical preparation with a unique way of targeting and fighting the fungi compared to commonly used allylamines and azoles. Although recent studies have shown various benefits of using ciclopirox, it is not commonly utilized.
Oral antifungal medications are also available for the management of dermatophytoses. They are especially useful in cases where the infection is chronic, recurrent, stubborn, or when the patient’s immune system is weakened. The most commonly prescribed oral medications are terbinafine and itraconazole due to their effective absorption and minimal drug interactions. Other medications, such as fluconazole and griseofulvin, are not as preferred due to their weaker adherence to the skin protein, keratin, and longer treatment periods. Oral ketoconazole is not recommended due to its potential for liver toxicity.
Topical and oral antibiotics can also be used in conjunction with antifungal treatments when a secondary bacterial infection is present.
There are some controversial and alternative treatments available as well, like the use of an ointment called Whitfield’s, topical corticosteroid, and antifungal therapy. While some studies suggest that combination therapy with steroids and antifungal creams may improve cure rates, these results have not been widely accepted due to low-quality evidence and potential complications. Currently, topical steroids are not recommended as part of a tinea cruris (jock itch) treatment regimen.
What else can Tinea Cruris be?
When trying to diagnose “tinea cruris”, a skin fungus that affects the groin area, doctors might also consider other skin conditions that can look the same. These include:
- Candidiasis
- Erythrasma
- Psoriasis
- Seborrheic dermatitis
Candidiasis, another type of fungal infection, is often seen in women. In men, it may also affect the scrotum and penis. This condition often presents with patches of skin irritation and ‘satellite’ spots around the rash, and there’s no clear center in the rash – all signs that it may be candida and not tinea cruris. Erythrasma, on the other hand, has a rash that doesn’t have an active border and it glows a coral-red color under a special light used for skin examinations, known as a Wood lamp.
Psoriasis might be another cause, but it usually also affects other areas of the body, not just the groin. Finally, seborrheic dermatitis can present with oily scales on a reddish skin patch.
What to expect with Tinea Cruris
People suffering from tinea cruris, often known as jock itch, usually see success rates of 80 to 90 percent when they undergo the correct treatment.
Possible Complications When Diagnosed with Tinea Cruris
Tinea cruris, a type of fungal infection, can be difficult to treat, and there is a high chance of it coming back. This can happen due to re-exposure from personal contacts, transferring the infection from another part of your body, infection by rare species such as animal-borne infections, misdiagnosis, drug resistance, or lack of adherence to the treatment plan. Use of steroidal creams might hide the symptoms of tinea cruris, making it harder to diagnose, and prolonged use can cause skin thinning and dilation of small blood vessels on the skin’s surface. Secondary bacterial infections can also result from tinea cruris.
In summary, complications of Tinea Cruris could include:
- Recurrence of infection
- Hidden symptoms due to steroid use
- Skin thinning and dilation of small blood vessels
- Secondary bacterial infection
- Majocchi’s granuloma—an uncommon ailment that causes a deep, inflammatory disease due to fungal infections breaching into the subcutaneous tissue. This can result from skin damage, lower body immunity, or topical steroid use condition
- A dermatophytid reaction—an allergic response happening at a different location from the original infection site
Preventing Tinea Cruris
When it comes to treatment and prevention of tinea cruris, also known as jock itch, it’s helpful to focus on measures that don’t involve medication. Things like wearing loose, comfortable clothes can help, and it’s recommended not to put on clothing until the skin underneath is fully dry.
Because jock itch can sometimes be spread from foot fungus (tinea pedis), walking barefoot should be avoided. Wearing protective shoes in public places can provide a safeguard against catching the infection.
Identifying and treating any contacts — be they human or pet — who might also be infected is a key step in stopping the spread. It’s important to avoid self-treating jock itch with over-the-counter antifungal creams or steroid creams. This can make the infection harder to get rid of and could also make it harder for a doctor to properly diagnose the condition.
