Major Research Findings

Tinea infections are superficial fungal infections caused by three species of fungi collectively known as dermatophytes. 3 These infections are often named after the body part affected, such as tinea corporis (general skin), tinea cruris (groin), and tinea pedis (feet). Accurate diagnosis is essential for effective treatment. Diagnosis is typically based on the history of the infection and clinical presentation, along with a direct microscopic examination of a potassium hydroxide preparation. A fungal culture or histologic examination is rarely needed for diagnosis.

The treatment of tinea infections requires attention to exacerbating factors, such as skin moisture, and selecting an appropriate antifungal agent. 3 Topical therapy is generally successful unless the infection covers a large area or is resistant to initial therapy. In these cases, systemic therapy may be required. Tinea corporis and cruris infections are typically treated for two weeks, while tinea pedis is treated for four weeks with an azole or for one to two weeks with allylamine medication. Treatment should continue for at least one week after the infection has clinically cleared. Newer medications require fewer applications and a shorter duration of use. Inflammation may necessitate the use of an agent with inherent anti-inflammatory properties or a combination antifungal/steroid agent. However, combination antifungal/steroid agents should be used with caution due to their potential to cause atrophy and other steroid-associated complications.

Treatment Summary

A variety of topical and oral antifungals are available to treat tinea infections. 4 Topical antifungals are typically the first-line treatment for many superficial dermatophytoses. Common antifungal agents include imidazoles, morpholines, and allylamines. The development of newer oral agents, such as fluconazole, itraconazole, and terbinafine, has enhanced the options for treating difficult-to-treat tinea infections. The antifungal efficacy and pharmacokinetic profiles of these drugs allow for shorter treatment durations and the innovative use of intermittent pulse regimens. While these modern formulations are well-tolerated and have a low risk profile, their response rates may not always meet the high expectations of in vitro studies.

8 Oral terbinafine is often prescribed at higher doses to treat dermatophyte infections, but it is not clear if these higher doses are more effective than the conventional dose. A randomized, controlled study compared the efficacy and safety of a daily dose of 250 mg oral terbinafine with 500 mg oral terbinafine, in addition to topical clotrimazole, in the treatment of tinea corporis and cruris. No significant differences were found in the clinical parameters between the two groups. However, the overall cure rates were relatively low, suggesting that oral terbinafine may not be the most effective treatment for tinea corporis and cruris, even at higher doses.

2 Luliconazole, an antifungal agent, is highly effective against Trichophyton spp. a major cause of dermatophytosis. However, luliconazole has limitations such as poor skin retention, low aqueous solubility, and poor skin penetration. Nanostructured lipid carriers (NLCs) have been formulated to overcome these limitations. NLCs enhance permeation by increasing skin occlusion and hydration. In vitro antifungal studies showed that a luliconazole NLC gel was more effective against Trichophyton rubrum than a marketed luliconazole cream. These findings suggest that luliconazole NLCs may offer a promising topical treatment option for tinea infections.

13 A bioactive compound, 1-heneicosanol, isolated from Streptomyces albidoflavus STV1572a, has shown promising antidermatophytic activity. In silico molecular docking studies revealed a strong interaction between 1-heneicosanol and squalene epoxidase, a key enzyme involved in fungal sterol biosynthesis. This finding was further supported by a sterol quantification assay, which confirmed the antidermatophytic mechanism of 1-heneicosanol. This study suggests that 1-heneicosanol may be a potential antidermatophytic compound for dermatophytic treatment.

The incidence of recurrent tinea infections after oral terbinafine therapy is increasing. 21 This highlights the need for more effective and long-lasting treatment options for tinea infections.

Benefits and Risks

Benefits Summary

The treatment of tinea infections with antifungal medications offers significant benefits. These medications effectively reduce symptoms and prevent the recurrence of infection. New treatment options have been developed that require fewer applications and have shorter treatment durations, improving patient convenience. Anti-inflammatory agents and combination antifungal/steroid agents can help manage inflammation associated with tinea infections.

Risk Summary

Antifungal medications can cause side effects, which can vary depending on the specific medication and the individual's sensitivity. Common side effects include gastrointestinal issues, skin irritation, and allergic reactions. Combination antifungal/steroid agents carry the risk of causing atrophy and other steroid-related complications.

Comparison of Studies

Similarities Among Studies

Several studies highlighted the prevalence of tinea infections worldwide. The studies also indicated that numerous antifungal medications are available for treating these infections, both topically and orally. The studies also acknowledged the importance of identifying the specific dermatophyte species responsible for the infection to ensure the most effective treatment.

Differences Among Studies

The studies differed in their focus. Some studies investigated specific treatment approaches for certain types of tinea infections, such as tinea corporis or tinea cruris. Other studies focused on the efficacy of specific antifungal agents, while some explored the development of new antifungal drugs. There were also differences in the study designs, sample sizes, and patient characteristics.

Consistency and Contradictions in Results

The studies consistently demonstrated that tinea infections are a common global health problem and that antifungal medications can effectively manage these infections. However, the results also highlighted the challenges of treating tinea infections, including the potential for resistance to antifungal agents and the need for longer treatment durations. The studies also indicated that the effectiveness of specific antifungal agents may vary, necessitating careful patient evaluation and consideration of individual factors.

Implications for Real-World Application

The research findings underscore the importance of early diagnosis and treatment of tinea infections to prevent complications and reduce the risk of recurrence. Individuals with recurrent tinea infections may benefit from ongoing monitoring and the use of long-term antifungal therapy to prevent infection recurrence. It is important to maintain good hygiene practices, such as washing hands frequently and avoiding contact with infected individuals, to minimize the risk of acquiring a tinea infection. When experiencing symptoms of a possible tinea infection, consulting a healthcare professional for accurate diagnosis and treatment is crucial.

Limitations of Current Research

Current research on tinea infections has limitations. There is a need for more comprehensive and robust studies to further investigate the effectiveness and safety of various antifungal agents, the mechanisms of resistance, and the long-term consequences of recurrent infections. Additionally, further research is necessary to understand the role of individual factors, such as genetics and immune status, in the development and treatment of tinea infections.

Future Research Directions

Future research should focus on developing more effective and longer-lasting treatment options for tinea infections, including investigating new antifungal agents and exploring innovative drug delivery systems. Research is also needed to better understand the mechanisms of resistance to antifungal agents and to develop strategies for overcoming resistance. Further research is required to explore the use of personalized medicine approaches to tailor treatment strategies based on individual patient characteristics.

Conclusion

Tinea infections are a prevalent global health concern that can significantly impact an individual's well-being. A variety of antifungal agents are available for treating these infections, but their effectiveness may vary depending on the specific type of infection, the causative agent, and individual patient factors. Early diagnosis and treatment are crucial for preventing complications and reducing the risk of recurrence. Maintaining good hygiene practices and consulting a healthcare professional for appropriate diagnosis and treatment are essential steps in managing tinea infections. Continued research is needed to develop more effective and long-lasting treatment options, overcome antifungal resistance, and personalize treatment strategies for improved patient outcomes.

Treatment List

Topical Antifungal Agents: imidazoles, morpholines, allylamines, luliconazole, sertaconazole, terbinafine. Oral Antifungal Agents: fluconazole, itraconazole, terbinafine. Combination antifungal/steroid agents. Anti-inflammatory agents.