Overview

Tinea manuum, also known as ringworm of the hand, is a fungal infection that affects the outer layer of the skin. Depending on the geographic location, the incidence of tinea manuum might vary from 0.3% to 13% and typically appears on the palm, back of the hands, or skinfolds between the fingers.¹ The most common clinical presentation of tinea manuum, according to a review of gathered cases, is "the two feet, one hand syndrome" (65%).¹  Adolescents and adults assigned male at birth (AMAB) are the most affected population, irrespective of age group.² 

Trichophyton rubrum is the most common dermatophyte causing tinea manuum.¹ 

Common symptoms include itchy, dry, round patches on the back of the hands and thickened skin on the palms. The infection usually spreads quickly from close contact with infected people, touching their objects, or touching surfaces harbouring the fungus, as well as from animals and soil. Individuals living in a tropical environment, visiting areas with hot and humid weather, or using public showers, locker rooms, indoor pools, and sports facilities are at higher risk of developing the infection.^1,2 Early treatment is essential to prevent the spread of the infection, leading to complications. Topical antifungal agents or medications are the first line of treatment suggested for tinea manuum.

What Are Topical Antifungals?

Topical antifungals are medications available in various forms, including creams, solutions, lotions, powders, gels, sprays, or lacquers, applied to the skin surface to treat fungal infections. These medications either kill the fungi or stop their growth.²

Types of Antifungal Agents Used for Tinea Manuum

Several topical and oral antifungal agents are available to treat tinea manuum. However, topical agents are preferred for mild cases due to their low risk of side effects or drug interactions.² Oral antifungal medications are indicated for moderate to severe cases.³ The main classes of topical antifungals used for tinea manuum include:

Azoles

They selectively inhibit lanosterol 14 alpha-demethylase, an essential enzyme in the synthesis of fungal cell ergosterol. Decreased levels of ergosterol increase cell membrane rigidity and permeability and disrupt the membrane-bound enzymes, inhibiting growth and ultimately causing cell death.^3,4

• Miconazole
• Clotrimazole

Allylamines

Allylamines inhibit squalene epoxidase, an essential enzyme involved in the synthesis of ergosterol. Inhibition of squalene epoxidase results in high levels of squalene accumulation, subsequently increasing membrane permeability and disrupting cellular organisation, ultimately causing cell death.^3,4

• Terbinafine
• Naftifine

Polyenes 

Polyene antifungals irreversibly bind to ergosterol in the fungal cell membrane, forming pores in the plasma membrane and resulting in loss of membrane integrity.^3,4

• Nystatin

Others 

Ciclopirox 

A synthetic hydroxypyridone derivative inhibits essential enzymes involved in mitochondrial electron transport and energy production. It is active against many fungi, including dermatophytes and yeast.^3,4

Tolnaftate

Thiocarbamate antifungal, inhibits squalene epoxidase and disrupts the synthesis of ergosterol, a vital component of the fungal cell membrane. Without ergosterol, the membrane becomes compromised, leading to cell death.⁵

Criteria for Selecting the Right Topical Antifungal

Spectrum of activity

Corticosteroids, often combined with topical antifungals, can cause side effects and may worsen existing fungal skin infections. Therefore, selecting an appropriate topical antifungal that does not contain a corticosteroid is essential.⁸

Antifungals like clotrimazole, miconazole, and terbinafine are effective against dermatophytes. In contrast, nystatin is effective against Candida infections; therefore, it should not be used for treating dermatophyte infections or yeast-like fungal infections.²

Formulation types

Ointments

Ointments are viscous, opaque, or translucent, and have a greasy texture. When applied to the skin, they form an occlusive layer that prevents water and heat loss. This occlusive effect also increases drug penetration, thereby improving the efficacy of the active ingredient. Ointments are most effective on areas of the skin with sparse hair. However, their greasy nature sometimes limits patient compliance and may be cosmetically undesirable.⁶

Creams

Creams are opaque and viscous formulations that are absorbed or evaporate when applied to the skin. They can be used all over the body, including the face, and are especially effective for intertriginous areas such as the armpit and genital regions. However, due to their shorter contact time, creams are less effective for skin hydration and prolonged drug delivery compared to ointments.⁶

Gels

Gels are usually thick and liquefy when they come in contact with warm skin, leaving a thin film that does not stain or feel greasy. They are particularly suitable for use in sebum-rich oily areas, such as the face, and in hairy areas of the body.⁶

Patient considerations 

Beyond the characteristics of antifungal medications, several factors related to the patient are crucial when selecting the most appropriate topical treatment, which include:

Skin sensitivity and allergies 

Some topical antifungals contain potential allergens in their vehicles, which cause allergic contact dermatitis. Hence, it is essential to prescribe a well-tolerated dose, considering the patient's skin type and history of sensitivities is essential.⁷

Compliance and ease of application

Simpler and shorter treatment regimens, such as once-daily applications, improve patient compliance. However, topical antifungals like imidazoles, which need a twice-daily application, may decrease adherence, especially once the symptoms disappear. Poor compliance can lead to reduced treatment benefits, biased assessments of efficacy, and increased healthcare costs.⁸

Cost and availability

The cost of topical antifungals may vary. Therefore, availability, efficacy, and patient tolerance should always be prioritised over cost alone.

Severity of infection 

Topical antifungals are generally sufficient for mild to moderate fungal infections. In case the topical treatment fails, doctors usually consider systemic options based on the severity of the infection. Oral antifungals like terbinafine or itraconazole may be prescribed to ensure complete eradication of the infection.⁹

Proper application of topical antifungals

Step-by-step guide for effective application of topical antifungals to the affected site(s):

• Wash your hands before and after application. If treating a hand or nail infection, wash your hands only before application 
• Clean and dry the affected area, apply a thin layer to the affected area and the surrounding area, and rub gently
• Do not get this medicine in your eyes. If you do, rinse out with plenty of cool tap water. 
• Use this medicine at regular intervals as prescribed 
• Complete the course of treatment as prescribed by your doctor or healthcare professional, even if the symptoms resolve 
• Do not stop using it except on your doctor's advice¹⁰

Note: Talk to your paediatrician about the use of these topical medications in children.

When to Seek Medical Advice

• Signs that topical antifungal agents are not working, such as persistent infection or worsening symptoms
• When the infection spreads to several other places on the body
• When oral antifungals may be needed (e.g., extensive infection, recurrent cases)
• When you notice an infection that has pus or discharge

FAQs

What is the best antifungal treatment for tinea manuum?

Mild cases of tinea manuum can be effectively treated with over-the-counter antifungal creams such as clotrimazole or miconazole. However, if the treatment is unsuccessful, doctors may prescribe oral antifungal agents such as terbinafine or itraconazole.

Should topical antifungals be rubbed in?

Yes, topical antifungals should be applied in small amounts to the affected area as a thin layer and rubbed gently. 

What is “The rule of Two” in tinea? 

Topical antifungals should be applied 2 cm beyond the visible margin of the lesion twice a day for at least 2 weeks, and continue the treatment for two more weeks beyond the disappearance of visible signs of infection.

Summary

Tinea manuum is a common fungal infection that affects the outer layer of skin, including the palm, the back of the hands, or between the fingers. The infection spreads quickly from infected individuals through touching their objects, or fungal-contaminated surfaces, animals, and soil. Topical antifungal medications such as terbinafine, miconazole, clotrimazole, and ciclopirox effectively treat mild cases with minimal side effects. These medications work by disrupting the fungal cell membrane formation and causing cell death. However, prescribing an appropriate topical antifungal agent depends on several factors, such as the spectrum of activity, formulation type, patient-specific factors, severity of infection, cost, and availability. 

Doctors should guide individuals on the proper application of topical antifungals-ensuring cleanliness, adherence to dosage, and completing the treatment course for successful resolution. Patients should be instructed to seek immediate medical attention if symptoms persist, worsen, or spread to other body parts. Adhering to treatment guidelines, maintaining good hand hygiene, and minimising exposure to contaminated environments can help prevent recurrence. Furthermore, educating individuals about the importance of treatment compliance and long-term hand care can reduce the risk of reinfection and promote overall skin health.