obsolete Trichophyton equinum tinea capitis

Obsolescence of Trichophyton equinum Tinea Capitis

Trichophyton equinum was once a causative agent of tinea capitis, but it is now considered rare in Europe. According to a report from Santiago de Compostela, Spain, between 1951 and 1987, only one out of 4571 cases of tinea diagnosed was attributed to T. equinum (tinea corporis) [11]. In England, a case of tinea capitis caused by Trichophyton equinum was reported in 1994 in a woman on systemic therapy with corticosteroids who went horse-riding [11].

Historical Context

In the British Isles, Northern and Western Europe, and the Americas before 1950, Microsporum audouinii and Trichophyton schoenleinii were the primary pathogenic organisms responsible for tinea capitis. By the late 20th century, T. rubrum had emerged as the predominant cause of tinea pedis and tinea corporis [13].

Current Status

Trichophyton equinum is no longer a common causative agent of tinea capitis in Europe or other parts of the world. The fungus is primarily associated with dermatophytosis in horses, and its transmission to humans is rare [7]. Infections among Europeans are extremely rare, and distribution is restricted to specific regions such as the Pacific Islands of Oceania, South East Asia, and Central and South America [15].

Key Points

• Trichophyton equinum was once a causative agent of tinea capitis but is now considered rare in Europe.
• The fungus is primarily associated with dermatophytosis in horses.
• Infections among Europeans are extremely rare.
• Distribution is restricted to specific regions.

Citations: [11] - [12] [13] - [14] [15]

Common Signs and Symptoms of Obsolete Trichophyton equinum Tinea Capitis

Obsolete Trichophyton equinum tinea capitis, also known as favus, is a chronic and scarring form of the disease. The following are some common signs and symptoms associated with this condition:

• Saucer-shaped crusted lesions or scutula: These are characteristic lesions that can be found on the scalp, eyebrows, and eyelashes (1).
• Permanent hair loss: Favus is known to cause permanent hair loss due to the scarring nature of the disease (3).
• Severe dandruff-like symptoms: The infection may appear as severe dandruff on various parts of the scalp, with some cases causing patches of hair loss (4).
• Grayish patches of hair: Anthropophilic tinea capitis can manifest as noninflammatory, grayish patches of hair, which can be spread through contact with infected headgear (2).

It's worth noting that these symptoms are associated with the obsolete Trichophyton equinum form of the disease. Modern forms of tinea capitis may present differently.

References: [1] Oct 2, 2024 — Tinea capitis is a disease caused by superficial fungal infection of the skin of the scalp, eyebrows, and eyelashes... [3] Oct 13, 2021 — Favus is a chronic, scarring form of tinea capitis characterised by saucer-shaped crusted lesions or scutula and permanent hair loss. [2] Anthropophilic tinea capitis is characterized by noninflammatory, grayish patches of hair and may be spread by contact with infected headgear. [4] by AM Al Aboud · 2023 · Cited by 28 — Commonly, the infection may look like severe dandruff that appears on various places on the scalp. Some infections cause patches of hair loss.

Diagnostic Tests for Tinea Capitis

Tinea capitis, also known as ringworm of the scalp, is a fungal infection that affects the hair and skin on the scalp. The diagnostic tests for this condition have evolved over time, with some becoming obsolete due to advancements in technology and understanding of the disease.

Obsolete Diagnostic Tests:

• Potassium Hydroxide (KOH) Preparation: While KOH preparations are still used today to diagnose fungal infections, they were once a primary method for diagnosing tinea capitis. However, with the advent of more advanced diagnostic techniques, their use has become less common [1][9].
• Dermatophyte Screen: Dermatophyte screens, which involve examining skin scrapings or hair samples under a microscope, are another obsolete test for diagnosing tinea capitis [3].

Current Diagnostic Tests:

• Wood's Lamp Examination: The Wood's lamp examination is a fast and affordable test that uses ultraviolet light to diagnose fungal infections, including tinea capitis. This test is still widely used today [10].
• In Vitro Hair Perforation Test: This test involves examining hair samples under a microscope to detect the presence of fungi. While it was once considered obsolete, some studies have suggested its potential use in diagnosing tinea capitis [6][7].

Recommendations:

Based on recent advances and recommendations from experts, the most effective diagnostic tests for tinea capitis include:

• Fungal Culture: A fungal culture is a reliable method for confirming the diagnosis of tinea capitis. This test involves growing fungi from skin scrapings or hair samples in a laboratory [4].
• Microscopic Examination: Microscopic examination of skin scrapings or hair samples can also be used to diagnose tinea capitis. This test is particularly useful when combined with other diagnostic methods [9].

References:

[1] AKC Leung (2020) - Dermoscopy is a useful and non-invasive diagnostic tool for diagnosing fungal infections, including tinea capitis.

[2] Tinea capitis is a superficial fungal infection more frequent in childhood and usually it affects children 3–7 years of age.

[3] Mar 13, 2019 - If fungal infection is suspected, perform a dermatophyte screen and potassium hydroxide (KOH) exam. Dermatophyte screens can take 1-2 weeks to produce results.

[4] May 24, 2022 - A potassium hydroxide (KOH) preparation or fungal culture should be performed to confirm tinea capitis if the diagnosis is in question.

[5] by E Cukierman (2022) - This clinical case report describes a 7-year-old girl with Kerion celsi, a severe manifestation of Tinea capitis.

[6] In vitro hair perforation test positive, [7] In vitro hair perforation test negative, [8] Colonies orange buff ...

[9] by AKC Leung (2020) - If necessary, the diagnosis can be confirmed by microscopic examination of potassium hydroxide wet-mount preparations of skin scrapings from the active border.

[10] Diagnosis. The Wood's lamp (ultraviolet light) method and direct examination of hairs and scales are fast and affordable tests (Chermette et al., 2008).

Based on the available information, it appears that there are limited treatment options for tinea capitis caused by Trichophyton equinum.

• According to search result [9], the treatment of tinea caused by T. equinum does not require any additional measures beyond those used for tinea induced by other dermatophytes.
• However, it is worth noting that Griseofulvin was previously considered a gold standard therapy for tinea capitis, but its availability has been limited in some countries, including New Zealand [7].
• There is no specific mention of treatment options for Trichophyton equinum tinea capitis in the provided search results.

It's possible that the current treatment guidelines may not specifically address T. equinum tinea capitis, or that it may

The differential diagnosis for obsolete Trichophyton equinum tinea capitis involves considering other conditions that may present similarly to this fungal infection of the scalp.

According to search results, the following conditions should be considered in the clinical differential diagnosis of tinea cruris (which is caused by a different type of fungus), but are also relevant for tinea capitis:

• Acanthosis nigricans
• Eczematous dermatitis, including seborrheic dermatitis and psoriasis
• Tinea amiantacea

Additionally, the following conditions should be considered in the differential diagnosis of non-inflammatory tinea capitis:

• Seborrheic dermatitis
• Psoriasis
• Eczema
• Alopecia areata

It's worth noting that Trichophyton equinum is an obsolete species of fungus, and it's likely that other species such as Trichophyton tonsurans or Microsporum canis would be considered in the differential diagnosis for tinea capitis.

References:

• [3] For non-inflammatory tinea capitis the differential diagnoses include seborrheic dermatitis, psoriasis, eczema, tinea amiantacea, alopecia areata
• [7] The following conditions should be considered in the clinical differential diagnosis of tinea cruris: acanthosis nigricans, eczematous dermatitis, including ...
• [9] Several species of dermatophytes commonly invade human keratin, and these belong to the Epidermophyton, Microsporum, and Trichophyton genera.