Whitney A. High, MD

Disclosures

August 10, 2009

Clinical Presentation: Tinea Barbae

History and Physical Examination

A 63-year-old white man presented with an eruption of the face and neck present for about 4 years. The rash was pruritic. He had been seen by a number of physicians over the years, but lacked a firm diagnosis. Prescribed topical corticosteroids led to transient improvement in his pruritus, but the rash had never resolved. He worked as an over-the-road truck driver, and he often hauled cattle from Wyoming to market in Denver, Colorado.

Upon physical examination, he had erythematous, scaling, and roughly annular eruption on the right face and neck (Figures 1 and 2).

Figure 1. Roughly annular scaling plaque of the face and neck in a 63-year-old man. Courtesy of Whitney A. High, MD.
 

Figure 2. Closer examination of the morphology of the scaling plaque of the face and neck in a 63-year-old man. Courtesy of Whitney A. High, MD.

Closer examination of the morphology of the scaling plaque of the face and neck in a 63-year-old man. Courtesy of Whitney A. High, MD.

Discussion of Diagnosis and Prior Treatment

A pruritic and scaling eruption of the face and neck, with a roughly annular distribution, is always cause for concern for the possibility of tinea. Tinea barbae, or a dermatophyte infection of the bearded face, is often associated with exposure to livestock, and his contact with cattle is an important clinical clue.[1]

Use of potent topical steroids would not only predispose to continued infection (due to local immunosuppression), but could also produce serious side effects from use of fluorinated steroids on the face, including atrophy, telangiectasias, and perioral dermatitis.[2] Empirical treatment with antibiotics or topical chemotherapy for actinic keratoses would not be prudent until fungal infection was excluded. Although herpetic folliculitis is in the differential for nearly any facial eruption such as this, the absence of a vesicular process and the chronicity of the eruption mitigate against this diagnosis.[3]

A KOH examination was performed (Figure 3).

Figure 3. Typical view of the KOH examination of scrapings of this patient's facial lesions. Courtesy of Whitney A. High, MD.

Results of KOH Examination

A KOH examination of skin scrapings, when performed by a person with experience in the interpretation, has a sensitivity of 77% to 88%.[4] In this case, branched hyphae were clearly visible, confirming the diagnosis and directing management for fungal infection.

In Latin "tinea" translates to "gnawing worm." Laypeople often refer to these eruptions as "ringworm," but the infections are fungal in nature. In dermatology, tinea refers to any superficial fungal infection caused by a dermatophyte, a type of fungus capable of using keratin as an energy substrate.[5]

Dermatologists generally follow the word "tinea" with a second word indicative of the site of infection, such as "tinea pedis" (feet, also called athlete's foot), "tinea capitis" (head), "tinea cruris" (groin, also called jock itch), or "tinea corporis" (body). Tinea barbae refers to dermatophyte infections of the bearded face. Tinea faciei is a similar infection of a face without terminal hairs, such as that of a woman or child.

Tinea barbae is a form of tinea with an interesting history. Prior to the widespread use of sterilization techniques, the condition was often spread by contaminated barbershop instruments.[6] In some countries with less economic resources, the barbershop has remained a viable source of infection for tinea barbae and for tinea capitis.[7]

Nowadays, tinea barbae is seen chiefly in dairy farmers and cattle ranchers,[1] but other animal sources, such as dogs and cats, have also been implicated in the acquisition of infection.[8] Because tinea barbae is most often acquired from animals, the zoophilic species of dermatophytes are most often involved, particularly Trichophyton mentagrophytes and Trichophyton verrucosum. Zoophilic species also typically engender greater inflammation than that of anthropophilic or geophilic dermatophytes, and the inflammation that may accompany tinea barbae may be substantial.

In culture, T mentagrophytes and T verrucosum can be distinguished on the basis of the following features (Table 1).

Table 1. Characteristics of Dermatophytes Involved in Tinea Barbae

Dermatophyte Species Microconidia, Macroconidia, and Hyphae Urease Test Hair Penetration Special Nutrient Requirements
Trichophyton mentagrophytes Spiral hyphae and grapelike clusters of microconidia Positive Positive None
Trichophyton verrucosum Rat tail-shaped macroconidia with characteristic chlamydospore formation at 35 C Variable Negative Thiamine and inositol

 

Treatment Considerations

Treatment of tinea infections is focused on 2 factors: (1) the amount of surface area affected and (2) the presence (or absence) of terminal hairs in the affected area. Topical treatment is impractical when large surface areas are affected; similarly, the presence of terminal hairs allows the fungus to track deeply down the follicular epithelium, also rendering topical therapy impractical.

Treatment of tinea barbae, which by definition involves the bearded face, involves use of an oral antifungal agent,[9] usually with griseofulvin, terbinafine, or itraconazole (Table 2).[10]

Table 2. Common Treatment Protocols for Tinea Barbae

Agent Mechanism of Antifungal Action Fungistatic or Fungicidal Typical Dose Duration of Treatment
Griseofulvin Interference with microtubule formation Fungistatic Either
500 mg once daily to twice daily (microsized)

or

333 mg once daily to twice daily (ultramicrosized)
2 weeks beyond resolution (usually 4-6 weeks)
Terbinafine Inhibition of squalene epoxidase Fungicidal 250 mg once daily 2-4 weeks
Itraconazole Inhibition of 14alpha-demethylase Fungistatic Either
200 mg twice daily x 1 week (pulse, may be repeated in 3 weeks)

or

100 mg twice daily x 4 weeks

From Dismukes WE, et al.[10]

Discussion of Treatment

Although clotrimazole, ciclopirox olamine, and miconazole are active against dermatophytes,[11] they are only available in topical formulations and are not often administered in the management of tinea barbae. Nystatin has no activity against dermatophytes.[10]

Case Wrap-up

This patient was treated with terbinafine (250 mg once daily x 2 weeks) and he resolved completely. Given that the condition was present for at least 3 years and had failed a variety of empirical treatments prescribed by other physicians, the patient was quite pleased with this outcome.

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