Background

Favus, or tinea favosa, is a chronic fungal infection of the skin and hair. It is caused by the dermatophyte fungus Trichophyton schoenleinii. Favus primarily affects the scalp, although it occasionally involves other body parts. The condition is characterized by the formation of yellowish, cup-shaped crusts or scutula on the scalp, which gives the appearance of a honeycomb.

These scutula result from the buildup of the fungus and its by-products within the hair follicles. The infection is highly contagious and can spread from person to person through direct contact with the infected individual or through contaminated objects like combs, hats, and towels.

The fungus responsible for favus thrives in warm and humid environments, making crowded living conditions and inadequate personal hygiene risk factors for its transmission. In severe and long-standing cases, favus can lead to permanent hair loss and scarring of the affected areas. 

Epidemiology

• Geographic Distribution: Favus has been historically more prevalent in some areas of Europe, Asia, and North Africa. It has been reported in Morocco, Algeria, Egypt, India, Iran, and Turkey. The infection is often found in rural and underprivileged areas with inadequate sanitation and crowded living conditions. 
• Age and Gender: Favus can affect individuals of all ages, but it is more commonly reported in children and young adults. There is no significant gender predilection for favus; it can affect both males and females. 
• Risk Factors: Poor personal hygiene and crowded living conditions are major risk factors for the transmission of favus. Individuals with compromised immune systems or certain underlying medical conditions may be more susceptible to developing severe or disseminated favus. 
• Incidence and Prevalence: Reliable and recent data on the global incidence and prevalence of favus are limited due to its rarity in many regions. Favus is considered endemic in some parts of North Africa and specific areas of Asia. 

Anatomy

Pathophysiology

• Fungal Invasion: The primary causative agent of favus is Trichophyton schoenleinii, a dermatophyte fungus. The infection typically starts with the penetration of the fungus into the hair follicles and the superficial layers of the scalp skin. 
• Fungal Growth and Colonization: Once inside the hair follicles, the fungus multiplies and colonizes the infected area. The fungus thrives in warm and humid environments, commonly found in areas with poor hygiene and overcrowded living conditions. 
• Keratin Degradation: Trichophyton schoenleinii is a keratinophilic fungus, which means it has a strong affinity for keratin, the protein found in the skin, hair, and nails. The fungus produces enzymes that can break down keratin, allowing it to utilize keratin as a nutrient source for growth and survival. 
• Formation of Scutula: As the infection progresses, the fungal growth leads to the accumulation of fungal elements and their by-products within the hair follicles. This accumulation forms characteristic yellowish crusts or scutula on the scalp, giving the appearance of a honeycomb. The scutula consists of fungal hyphae, keratin debris, and inflammatory cells. 
• Inflammatory Response: The fungus and its by-products trigger an immune response from the host. The body’s immune system attempts to combat the infection by recruiting inflammatory cells to the affected area. 
• Tissue Damage: Chronic inflammation and the accumulation of fungal elements can lead to tissue damage and destruction. In severe and long-standing cases, the infection can cause permanent hair loss and scarring of the affected areas. 
• Contagious Nature: Favus is highly contagious, and the infection can spread from person to person through direct contact with an infected individual or through contaminated objects like combs, hats, and towels. 

Etiology

The etiology of favus is primarily attributed to the dermatophyte fungus Trichophyton schoenleinii. This specific fungus is responsible for causing the chronic fungal infection known as favus. Trichophyton schoenleinii is a keratinophilic fungus, which means it has a strong affinity for keratin, the protein present in the skin, hair, and nails.

The infection typically begins with the penetration of the fungus into the hair follicles and the superficial layers of the scalp skin. Once inside the hair follicles, the fungus multiplies and colonizes the infected area. It thrives in warm and humid environments, making crowded living conditions and inadequate personal hygiene risk factors for its transmission. 

Genetics

Prognostic Factors

• Duration of Infection: The length of time the infection has been present can impact the prognosis. Longer durations of untreated or inadequately treated favus may result in more extensive tissue damage and more challenging recovery. 
• Extent of Involvement: The amount of affected scalp surface area and the depth of involvement can affect the prognosis. Cases with larger and more severe lesions may take longer to heal and have a higher risk of complications. 
• Immune Status: The individual’s immune status can play a role in the severity and course of the infection. Immunocompromised individuals, such as those with HIV/AIDS or other immune system disorders, may experience more severe and disseminated forms of favus. 
• Underlying Health Conditions: Other medical conditions, such as diabetes or malnutrition, can impact the body’s ability to fight the infection and influence the prognosis. 
• Compliance with Treatment: Adherence to the prescribed treatment plan, including proper use of antifungal medications and regular follow-up, is crucial for successful management and a favorable prognosis. 
• Presence of Complications: Complications, such as secondary bacterial infections or severe scarring, can affect the outcome of the infection. 
• Response to Treatment: The response to antifungal therapy can provide valuable prognostic information. A prompt and favorable response to treatment is associated with a better prognosis. 
• Hygiene and Living Conditions: Individuals living in crowded or unhygienic conditions may be at a higher risk of recurrent or prolonged infections. 

Clinical History

Age Group: Favus primarily affects children and young adults. It is more commonly reported in individuals aged 5 to 20, although it can occur at any age. 

Physical Examination

• Scalp Examination: The dermatologist will examine the scalp for characteristic yellowish crusts or scutula. These scutula have a cup-shaped appearance resembling a honeycomb and are a hallmark feature of favus. The scutula typically vary in size and may have a dark, raised border with a central yellowish depression. 
• Hair Examination: The hair in the affected areas of the scalp will be assessed for changes in texture, such as being dull, brittle, and easily breaking off. In advanced cases, the affected regions may have significant hair thinning or even complete hair loss (alopecia). 
• Skin Examination: If favus has spread to other areas of the body, such as the face, neck, or trunk, the dermatologist will examine these regions for scutula or other signs of infection. 
• Odor Assessment: The healthcare professional may inquire about any characteristic odor emanating from the affected scalp. In advanced cases, favus-infected areas may emit a foul smell due to the accumulation of keratin debris and fungal elements. 
• Skin Sensations: The person may report itching or pruritus in the affected areas due to the inflammatory response triggered by the fungus. 
• Lymph Node Examination: The nearby lymph nodes, especially those in the neck region, may be palpated to assess for any signs of lymphadenopathy (swollen lymph nodes), which could indicate a systemic response to the infection. 
• Systemic Examination: In some cases, the dermatologist may perform a general physical examination to assess for signs of systemic involvement or underlying health conditions contributing to the infection. 

Age group

Associated comorbidity

• Hygiene and Living Conditions: Favus is more prevalent in areas with poor hygiene and crowded living conditions, facilitating fungus transmission from person to person. 
• Immunocompromised Individuals: Individuals with compromised immune systems, such as HIV/AIDS or other immune disorders, may be more susceptible to severe or disseminated forms of favus. 

Associated activity

Acuity of presentation

The acuity of favus presentation can vary depending on factors such as the duration of the infection and the individual’s immune response. In general: 

• Chronic and Slow-Progressing: Favus typically presents as a chronic and slowly progressive infection. The fungus grows gradually within the hair follicles, leading to the formation of scutula over time. 
• Delayed Diagnosis: Favus can often be misdiagnosed or mistaken for other skin conditions, leading to delayed diagnosis and treatment initiation. 
• Recurrence: Favus tends to recur, especially if treatment is incomplete or there are persistent infection sources in the living environment. 

Differential Diagnoses

• Alopecia Areata: Alopecia areata is an autoimmune condition that causes patchy hair loss on the scalp or other body areas. It can sometimes be mistaken for favus due to hair loss in both conditions. 
• Seborrheic Dermatitis: Seborrheic dermatitis is a common skin condition that leads to red, itchy, and scaly patches on the scalp and other oily areas of the skin. It may have a similar appearance to the early stages of favus. 
• Psoriasis: Psoriasis is a chronic skin condition characterized by red, scaly plaques that can affect the scalp and other body parts. It may appear like favus, especially if thick scales are present. 
• Impetigo: Impetigo is a bacterial skin infection that can lead to honey-colored, crusty lesions on the scalp or other body areas. The appearance of these lesions can sometimes be mistaken for favus scutula. 
• Eczema (Atopic Dermatitis): Eczema is a chronic inflammatory skin condition that can cause red, itchy, and scaly patches on the scalp and other body areas. In some cases, it may be confused with early-stage favus. 
• Scalp Ringworm (Tinea Capitis): Scalp ringworm is a fungal infection caused by various dermatophyte fungi, including Trichophyton tonsurans and Microsporum canis. The appearance of scalp ringworm may be like favus in some cases. 
• Kerion: Kerion is a severe inflammatory response to a fungal scalp infection. It can result in large, painful, and pus-filled nodules, which may be mistaken for advanced stages of favus. 
• Contact Dermatitis: Contact dermatitis occurs when the skin comes into contact with an irritating substance, leading to red, itchy, and inflamed patches. It may be considered a differential diagnosis, especially if there is a history of exposure to potential allergens or irritants. 

Laboratory Studies

Imaging Studies

Procedures

Histologic Findings

Staging

Treatment Paradigm

The treatment paradigm of favus (tinea favosa) typically involves a combination of antifungal medications, proper hygiene practices, and management of complications. The main goals of treatment are to eradicate fungal infection, promote healing of the affected areas, prevent complications, and reduce the risk of transmission to others. Here is the general treatment paradigm for favus: 

Antifungal Medications: 

• Oral Antifungals: The primary treatment for favus is oral antifungal medications. The most used antifungal for treating favus is griseofulvin. Terbinafine and itraconazole may also be effective alternatives. These medications help to eradicate the causative fungus from the body. 
• Topical Antifungals: In some cases, topical antifungal creams or lotions may complement oral antifungal therapy and treat localized infections. 

Anti seborrheic Shampoos: 

Antiseborrheic shampoos can help remove the crusts or scutula from the scalp and improve the response to antifungal treatment. These shampoos may contain ingredients like salicylic acid or sulfur. 

Scalp Care and Hygiene: 

Good scalp hygiene is crucial for preventing the spread of the infection and promoting healing. Regular washing and cleaning of the scalp with mild, non-irritating shampoos are recommended. Combing the hair gently to remove loose scales and debris can also aid treatment. 

Follow-up and Monitoring: 

Regular follow-up with a healthcare professional is essential to monitor the response to treatment, detect any complications, and adjust the treatment plan as needed. In some cases, long-term antifungal therapy may be required to prevent recurrence. 

by Stage

by Modality

Chemotherapy

Radiation Therapy

Surgical Interventions

Hormone Therapy

Immunotherapy

Hyperthermia

Photodynamic Therapy

Stem Cell Transplant

Targeted Therapy

Palliative Care

use-of-a-non-pharmacological-approach-for-treating-favus

• Topical antiseptic treatments: Regularly cleaning the affected scalp with antiseptic solutions can help control bacterial infections often accompanying favus. Mild antiseptic solutions like povidone-iodine can be applied topically. 
• Warm compresses: Warm compresses can help soften the crusts and scabs that form on the scalp due to favus, making it easier to remove them gently without causing further irritation. 
• Herbal remedies: Some herbal remedies may have antifungal properties and can be adjunctive treatments. For example, aloe vera gel or neem (Indian lilac) paste might be soothing and help reduce inflammation. 
• Proper hygiene and hair care: Maintaining good scalp hygiene is essential to prevent the spread of infection and improve overall healing. Regularly washing the hair with mild shampoo can help in this regard. 
• Nutrition: A balanced diet with adequate nutrients, particularly vitamins, and minerals, is crucial for maintaining a healthy immune system, which plays a role in fighting fungal infections. 
• Stress management: Stress can weaken the immune system and may contribute to the persistence of fungal infections. Encouraging stress-reduction techniques like meditation, yoga, or relaxation exercises can be beneficial. 

Role of Topical Antifungal Medications for the Treatment of Favus

Topical antifungal medications play a significant role in the treatment of favus, especially in cases where the infection is localized to the skin and scalp.

These medications are applied directly to the affected areas and work to eliminate fungal infection locally.

Topical antifungals are often used as a first-line treatment for mild cases of favus or as a supplementary therapy in combination with systemic (oral) antifungal medications for more severe or extensive infections. 

Ketoconazole: Ketoconazole is an antifungal medication in the azole class of drugs. It is used to treat a wide range of fungal infections, including some types of dermatophytes (the group of fungi that cause favus). However, it is more commonly employed in the treatment of other fungal skin infections such as ringworm (tinea corporis), athlete’s foot (tinea pedis), and fungal infections of the nails (onychomycosis). 

Selenium sulfide: Selenium sulfide is an antifungal agent used primarily to treat various skin conditions, including dandruff and seborrheic dermatitis. It is commonly found in medicated shampoos, where it can help control fungal growth on the scalp and reduce symptoms like scaling and itching.

While selenium sulfide has antifungal properties and can be useful in managing certain scalp fungal infections, it is not typically used as a standalone treatment for favus. Instead, it may be employed as an adjunctive therapy to help improve scalp hygiene and control secondary bacterial infections due to fungal infection. 

Role of Oral Antifungal agents for the treatment of Favus

Oral antifungal agents are crucial in treating favus, especially in moderate to severe cases or when the infection is extensive and not effectively managed with topical treatments alone. Oral antifungal medications are systemic treatments circulating through the bloodstream to target the fungal infection internally. 

Griseofulvin- Griseofulvin works by inhibiting the synthesis of fungal cell walls, preventing the fungi from spreading and reproducing. The duration of griseofulvin treatment for favus can vary depending on the severity of the infection and the patient’s response to the medication.

Treatment often lasts several weeks to months to ensure complete eradication of the fungal infection. It is particularly effective against the dermatophytes, the fungi group responsible for causing favus. 

use-of-intervention-with-a-procedure-in-treating-favus

The primary treatment for favus involves the use of antifungal medications, both topical and systemic, to eliminate the fungal infection.

In some cases, when there are severe complications related to favus, such as secondary bacterial infections, excessive crusting, or inflammation, additional procedures or interventions may be required to manage these complications.

These interventions aim to support the overall treatment and promote healing of the affected areas. 

• Debridement: In cases of excessive crusting and scaling on the scalp, debridement (removal of dead tissue) may be performed to improve the efficacy of topical antifungal treatments and to promote a healthier scalp environment. 
• Drainage of Abscesses: If secondary bacterial infections or abscesses are present, drainage may be necessary to alleviate pain and reduce the risk of further complications. 
• Wound Care: Proper wound care techniques may be employed to keep the affected areas clean and prevent infection. 
• Corticosteroid Injections: In some cases of severe inflammation and itching, corticosteroid injections may reduce inflammation and discomfort. 
• Surgical Consultation: In rare cases with complications like a deep-seated abscess or significant tissue damage, a surgical consultation may be needed for further assessment and intervention. 

use-of-phases-in-managing-favus

The general phases involved in managing favus: 

• Diagnosis and Evaluation: The first phase involves proper diagnosis by a qualified healthcare professional, typically a dermatologist. The dermatologist will examine the affected areas and may perform a fungal culture to confirm the presence of Trichophyton schoenleinii, the fungus responsible for favus. 
• Acute Treatment Phase: The acute treatment phase focuses on the active eradication of the fungal infection. The primary treatment is usually topical and systemic antifungal medications to target and kill the fungus. Oral antifungal medications such as griseofulvin are commonly prescribed and taken for several weeks to months, depending on the severity of the infection and the patient’s response to treatment. In some cases, topical antifungal medications may be adjunctive treatments to control the infection on the scalp’s surface. 
• Monitoring and Follow-up: During the treatment phase, regular follow-up appointments with the healthcare provider are essential to monitor the patient’s progress and response to treatment. Any side effects or complications are addressed promptly, and adjustments to the treatment plan may be made as needed. 
• Resolution of Infection: The treatment continues until the infection is resolved, as determined by clinical improvement and negative follow-up fungal cultures. To ensure complete fungus eradication, Patients must complete the course of prescribed medications, even if symptoms improve. 
• Post-Treatment Phase: After successfully resolving the infection, a post-treatment phase focuses on preventing recurrence and promoting healing of the affected areas. Hygiene and hair care practices are emphasized to maintain a healthy scalp environment. The patient may be advised to continue using topical antifungal shampoos or other products for a period to prevent relapse. 
• Long-Term Follow-up: Periodic follow-up visits are recommended to monitor for any signs of recurrence and to ensure long-term success in managing the condition. 

Medication

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References

Favus:pubmed.ncbi.nlm.nih 

Favus of the scalp:pubmed.ncbi.nlm.nih 

Tinea capitis favus: pubmed.ncbi.nlm.nih 

Molecular taxonomy:pubmed.ncbi.nlm.nih