This 48-year-old dairy farmer presented with a 3-month history of boggy, suppurative papules and nodules with crusts on his right cheek. He had been using over-the-counter topical antibiotics, antifungals and topical corticosteroid creams and ointments since the lesions appeared. However, these treatments did not improve the lesions.
On physical examination, we noted a large inflammatory plaque extending from his sideburn to the submandibular area on the right side of his face. This plaque was studded with confluent follicular papules, pustules and nodules. There was also a 2 cm x 3 cm ulceration, serum exudate and crusts with areas of alopecia. No cervical or occipital lymphadenopathy was noted.
What Is Your Diagnosis?
Diagnosis: Tinea Barbae Caused by Trichophyton verrucosum
About this Condition Tinea barbae, or sycosis barbae, is an acquired dermatophytosis of the beard. It occurs worldwide with higher incidence in agricultural areas, particularly in patients who have close contact with farm animals.1-3
The Responsible Dermatophytes
Several dermatophytes can cause tinea barbae including zoophilic and anthropophilic organisms.
• Zoophilic dermatophytes. Trichophyton mentagrophytes var granulosum and Trichophyton verrucosum are the most common causative agents. These species tend to produce an inflammatory suppurative infection in humans, although the infection in animals may be subclinical.1,2 •
Anthropophilic dermatophytes. The most common causative pathogens are Trichophyton rubrum and Trichophyton violaceum. However, Trichophyton megninii, and Trichophyton schoenleinii also may cause tinea barbae, especially in endemic regions. Tinea barbae may also result from autoinoculation from tinea pedis or onychomycosis.
Trichophyton species are most common pathogenic organisms, thus the term trichophytosis barbae is also used. Microsporum and Epidermophyton species also cause tinea barbae but are rare.
In this case, Gram stain and bacterial cultures of the draining pustules were negative. Potassium hydroxide preparation showed hyphae, and cultures yielded T. verrucosum.
More on Inflammatory Tinea Barbae and T. Verrucosum
In its severe form, inflammatory tinea barbae presents as a unilateral kerion or kerion-like, with edematous nodules and abscesses around hair follicles. Hairs are usually loose or absent, and should be painlessly removed for examination. This variety of tinea barbae is frequently associated with generalized symptoms, such as regional lymphadenopathy, malaise and fever. Our patient however, did not present with generalized symptoms or lymphadenopathy.
Cattle or horses are the main host for T. verrucosum, although this pathogen usually causes “cattle ringworm.” Transmission may occur through direct contact or indirectly by infected animal hair on clothing, or in contaminated stalls, barns, or feed where it may remain viable for years.1 A clue to the diagnosis would be a history of dairy farmer rubbing his face against the cow’s skin while milking.
Confirming the Diagnosis
Scale scrapings and removed hairs should be examined in 10% to 20% KOH for hyphae and spores. T. verrucosum exhibits an ectothrix pattern of hair invasion with spores along the surface of hair shafts.
Skin biopsy with fungal stains may also be useful to identify fungal elements; however, inflammation may be so severe that there may be sparse or absent fungi by microscopy or culture. Perifollicular granulomatous infiltrate with disrupted follicles and microabscesses are common histopathological features.2
Culture is easily performed by vigorously rubbing a moist, sterile cotton swab over the infected area and streaking on agar. T. verrucosum grows well in Sabouraud’s agar or Dermatophyte Test Medium, although it takes up to 3 weeks to identify small granular colonies.1-3 Identification of the particular organism, however, is not necessary because it does not affect clinical management.
It is important to differentiate fungal sycosis barbae from the more common sycosis vulgaris, or bacterial folliculitis caused by Staphylococcus aureus. The latter is typically bilateral and symmetric in distribution with pustules and papules around hair follicles. Hairs are generally intact, and their removal is painful. However, T. verrucosum can cause pustular tinea barbae in farmers that may be mistaken for a S. aureus infection by clinicians.4 Contact dermatitis, folliculitis caused by herpes simplex and molluscum contagiosum viruses may also mimic tinea barbae, but can usually be ruled out by history, cultures and patch testing.1,3 Verrucous epidermophytosis, caused by Epidermophyton floccosum, presents with more diffusely elevated wart-like lesions; however, this is a rare infection.
Treating and Preventing this Condition
Oral antifungals for 1 to 3 months are usually required to eradicate the fungus. If your patient has highly inflamed kerions, consider a short course of systemic steroids to reduce inflammation.3 Local care with wet compresses, and debridement of crusts and removal of debris are recommended as adjunctive treatments.
Classically, griseofulvin, either in microsized form (Grifulvin V) at doses ranging from 500 mg to 1000 mg/day, or ultramicrosized form (Gris-PEG) at doses ranging from 375 mg to 1000 mg/day, was the preferred therapy. This should be continued for 2 weeks after complete clinical resolution.
Newer antifungals such as itraconazole (Sporanox), fluconazole (Diflucan) and terbinafine (Lamisil) have had success in children to treat inflammatory tinea capitis, and in adults to treat tinea barbae at different doses and regimens.5 Recently, Maeda, et al. reported a patient with a good clinical response using itraconazole 100 mg/day for 2 months; the patient remained disease-free at 3.5 years.6 Our patient was treated with terbinafine 250 mg/day for 8 weeks with complete resolution of lesions and no residual alopecia. All of these new antifungal drugs are generally well tolerated.
In addition to treating infected patients, a vaccine is available for all live cattle to prevent the spread of T. verrucosum infection. Eliminating the source of infection is very important. If farm workers become infected, all the animals on the farm should be examined. To prevent spread of infection by autoinoculation, it is recommended to treat all other fungal skin infections, such as tinea pedis or onychomycosis.
If adequately treated, inflammatory tinea barbae resolves spontaneously within a few weeks to months. Lack of treatment however, may result in complications including sinus tract formation, secondary bacterial infection, hyperpigmentation and scarring alopecia. Severely immunocompromised individuals are at risk for disseminated dermatophytosis.2,6,7
So next time you see a patient with similar lesions —keep both T. verrucosumand the patient’s farmyard in your mind. The answer to the simple question, “Are you a dairy farmer?”, may suggest the diagnosis of T. verrucosum in the proper clinical setting.8 So, do not miss it!
Dr. Khachemoune’s Pearls
Remember these tidbits about inflammatory tinea barbae caused by T. verrucosum.
• Usually a dairy farmer — ask the patient about his job
• Unilateral involvement of the beard area
• Kerion or Kerion-like lesions
• Fever and lymphadenopathy may be present
• Examine the patient for other fungal infections
• Treat with oral antifungals
• Consider having the patient’s co-workers examined
• A veterinarian’s opinion for the herd may be appropriate.
Do you have a case you’d like to see published in this column? If so, please send a write-up (about 600 to 800 words) and an image of the patient’s condition. You may also include a follow-up image of the patient to accompany the discussion portion of the case. Please send materials to: Dr. Amor Khachemoune, Georgetown University Medical Center, Division of Dermatology, 3800 Reservoir Road, NW 5PHC, Washington, DC 20007. Or e-mail them to email@example.com.