eMedicine Specialties > Dermatology > Fungal Infections
Tinea Capitis: Differential Diagnoses & Workup
Updated: Sep 11, 2009
- Overview
- Differential Diagnoses & Workup
- Treatment & Medication
- Follow-up
- Multimedia
Differential Diagnoses
Other Problems to Be Considered
Bacterial folliculitis
Dissecting folliculitis (folliculitis decalvans)
Abscess
Neoplasia
Pyoderma
Secondary syphilis
Seborrheic dermatitis occurs in older children and, unlike tinea capitis, does not cause hair loss. In some cases of tinea capitis, the erythematous scaly lesions closely resemble those seen in seborrheic dermatitis; however, in seborrheic dermatitis, hairs are not broken. Seborrheic dermatitis and psoriasis may cause accumulation of scales in matted masses on the scalp. Scales are more prominent in psoriasis, and hairs are not broken.
Impetigo may be difficult to distinguish from inflammatory tinea capitis, although pain is less severe in tinea capitis, and hairs tend to be seated firmly in impetigo. Alopecia areata also causes circumscribed areas of hair loss similar to tinea capitis, but alopecia areata does not cause scaling. Lesions may have an erythematous border in the early stages of the disease, but this reverses to normal color at later stages. The exclamation mark hairs seen in alopecia areata, in which broken hairs taper from the fractured end toward the skin surface, are pathognomonic.
In secondary syphilis, areas of alopecia have a characteristic moth-eaten appearance or resemble alopecia areata. Serologic testing for the presence of treponemal antibody (rapid plasma reagin and Treponema -specific tests, eg, microhemagglutination– Treponema pallidum test) and testing by special silver impregnation histochemical stain (Warthin-Starry stain) for the demonstration of treponemal organisms aid in the accurate diagnosis of syphilis.
The patient may present with a generalized eruption of itchy papules, particularly around the outer helix of the ear, occurring as a reactive phenomenon (an id response). These symptoms may start with the introduction of systemic treatment for tinea capitis; thus, they be mistaken for a drug reaction.
Workup
Laboratory Studies
- Laboratory diagnosis of tinea capitis depends on examination and culture of skin rubbings, skin scrapings, or hair pluckings (epilated hair) from lesions.
- Before specimen collection, any ointment or other local applications present should be removed with alcohol.
- Infected hairs appearing as broken stubs are best for examination. They can be removed with forceps without undue trauma or collected by gentle rubbing with a moist gauze pad; broken, infected hairs adhere to the gauze. A toothbrush may be used in a similar fashion.3 Alternatively, affected areas can be scraped with the end of a glass slide or with a blunt scalpel to harvest affected hairs, broken-off hair stubs, and scalp scale. This is preferable to plucking, which may remove uninvolved hairs. Scrapings may be transported in a folded square of paper. Skin specimens may be scraped directly onto special black cards, which make it easier to see how much material has been collected and provide ideal conditions for transportation to the laboratory; however, affected hairs are easier to see on white paper than on black paper.
- Definitive diagnosis depends on an adequate amount of clinical material submitted for examination by direct microscopy and culture. The turn-around time for culture may take several weeks.
- Selected hair samples are cultured or allowed to soften in 10-20% potassium hydroxide (KOH) before examination under the microscope. Examination of KOH preparations (KOH mount) usually determines the proper diagnosis if a tinea infection exists.
- Conventional sampling of a kerion can be difficult. Negative results are not uncommon in these cases. The diagnosis and decision to treat lesions of kerion may need to be made clinically. A moistened standard bacteriological swab taken from the pustular areas and inoculated onto the culture plate may yield a positive result.4
- Microscopic examination of the infected hairs may provide immediate confirmation of the diagnosis of ringworm and establishes whether the fungus is small-spore or large-spore ectothrix or endothrix.
- Culture provides precise identification of the species for epidemiologic purposes.5 Primary isolation is carried out at room temperature, usually on Sabouraud agar containing antibiotics (penicillin/streptomycin or chloramphenicol) and cycloheximide (Acti-Dione), which is an antifungal agent that suppresses the growth of environmental contaminant fungi. In cases of tender kerion, the agar plate can be inoculated directly by pressing it gently against the lesion. Most dermatophytes can be identified within 2 weeks, although T verrucosum grows best at 37°C and may have formed only into small and granular colonies at this stage. Identification depends on gross colony and microscopic morphology. Specimens should be inoculated on to primary isolation media, such as Sabouraud dextrose, and incubated at 26-28°C for 4 weeks. The growth of any dermatophyte is significant.
- In some cases, other tests involving nutritional requirements and hair penetration in vitro are necessary to confirm the identification.
- Wood lamp examination: In 1925, Margarot and Deveze observed that infected hairs and some fungus cultures fluoresce in ultraviolet light. The black light commonly is termed Wood lamp. Light is filtered through a Wood nickel oxide glass (barium silicate with nickel oxide), which allows only the long ultraviolet rays to pass (peak at 365 nm). Wood lamp examination is useful for certain ectothrix infections (eg, those caused by M canis, M audouinii, Microsporum rivalieri). In cases with endothrix infection, however, negative Wood lamp examination findings are of no practical value for screening or monitoring infections.
- Hairs infected by M canis, M audouinii, M rivalieri, and M ferrugineum fluoresce a bright green to yellow-green color (see Media File 7).
- Hairs infected by T schoenleinii may show a dull green or blue-white color, and hyphae regress leaving spaces within the hair shaft.
- T verrucosum exhibits a green fluorescence in cow hairs, but infected human hairs do not fluoresce.
- The fluorescent substance appears to be produced by the fungus only in actively growing infected hairs.
- Infected hairs remain fluorescent for many years after the arthroconidia have died.
- When a diagnosis of ringworm is under consideration, the scalp is examined under a Wood lamp. If fluorescent infected hairs are present, hairs are removed for light microscopic examination and culture. Infections caused by Microsporum species fluoresce a typical green color.
- Unfortunately, most tinea capitis infections in North America are caused by T tonsurans and do not demonstrate fluorescence.6
- In favus, infected hairs appear yellow.
Wood lamp examination of a gray-patch area on the scalp (same patient as Media File 1). In Microsporum canis infection, scalp hairs emit a diagnostic brilliant green fluorescence. Trichophyton tonsurans does not fluoresce with Wood lamp.
- Serology is not required for a diagnosis of dermatophytosis.
- Videodermatoscopy: A small study in patients with tinea capitis from M canis found that comma hairs were a prominent and distinctive feature on videodermatoscopy; comma hairs were not seen in patients with alopecia areata.7
Histologic Findings
Skin biopsy with particular emphasis on examination of infected hairs with special histochemical stains aids in the identification of the causative fungus, especially in cases of fungal folliculitis (Majocchi granuloma) and onychomycosis. Bullous tinea demonstrates subepidermal edema and reticular degeneration of the epidermis. Tinea corporis demonstrates subacute and chronic dermatitis with or without follicular inflammation and destruction. Suppurative folliculitis may be present. In the mildest form, hyperkeratosis, parakeratosis, spongiosis, slight vasodilatation, and a perivascular inflammatory infiltrate in the upper dermis are present. Fungal hyphae can be demonstrated using routine hematoxylin and eosin stain, and identification can be facilitated by using special stains. Periodic acid-Schiff stain with diastase digestion or counterstained with green dye facilitates identification of fungal elements.
Photomicrograph depicting an endoectothrix invasion of a hair shaft by Microsporum audouinii. Intrapilary hyphae and spores around the hair shaft are seen (hematoxylin and eosin stain with Periodic acid-Schiff counterstain, magnification X 250).
Fungi are seen sparsely in the stratum corneum (see Media File 5). Hyphae extend down the hair follicle, growing on the surface of the hair shaft. Hyphae then invade the hair, penetrate the outermost layer of hair (ie, cuticle), and proliferate downward in the subcuticular portion of the cortex, gradually penetrating deep into the hair cortex. Pronounced inflammatory tissue reaction with follicular pustule formation surrounding hair follicles is seen in patients with the clinical form of infection termed kerion celsi (see Media File 6).
Fungal hyphae and yeast cells of Trichophyton rubrum seen on the stratum corneum of tinea capitis. Periodic acid-Schiff stain, magnification 250X.
Pronounced inflammatory tissue reaction with follicular pustule formation surrounding a hair follicle seen in a patient with clinical form of infection, termed kerion celsi. No fungal hyphae or spores were identified in the lesion in either tissue sections or culture. Fluorescein-labeled Trichophyton mentagrophytes antiserum cross-reacted with antigens of dermatophyte in the infected hairs within the pustule (hematoxylin and eosin stain, magnification X 75).
In endothrix infection, spherical–to–box-like spores are found within the hair shaft. This type of infection is caused by T tonsurans or T violaceum.
In ectothrix infection, organisms form a sheath around the hair shaft. In contrast to endothrix infection, destruction of the cuticle by hyphae and spores occurs.
More on Tinea Capitis |
| Overview: Tinea Capitis |
 Differential Diagnoses & Workup: Tinea Capitis |
| Treatment & Medication: Tinea Capitis |
| Follow-up: Tinea Capitis |
| Multimedia: Tinea Capitis |
| References |
| « Previous Page | Next Page » |
References
Seebacher C, Bouchara JP, Mignon B. Updates on the epidemiology of dermatophyte infections. Mycopathologia. Nov-Dec 2008;166(5-6):335-52. [Medline].
Kondo M, Nakano N, Shiraki Y, Hiruma M, Ikeda S, Sugita T. A Chinese-Japanese boy with black dot ringworm due to Trichophyton violaceum. J Dermatol. Mar 2006;33(3):165-8. [Medline].
Akbaba M, Ilkit M, Sutoluk Z, Ates A, Zorba H. Comparison of hairbrush, toothbrush and cotton swab methods for diagnosing asymptomatic dermatophyte scalp carriage. J Eur Acad Dermatol Venereol. Mar 2008;22(3):356-62. [Medline].
Friedlander SF, Pickering B, Cunningham BB, Gibbs NF, Eichenfield LF. Use of the cotton swab method in diagnosing Tinea capitis. Pediatrics. Aug 1999;104(2 Pt 1):276-9. [Medline].
Bonifaz A, Isa-Isa R, Araiza J, Cruz C, Hernández MA, Ponce RM. Cytobrush-culture method to diagnose tinea capitis. Mycopathologia. Jun 2007;163(6):309-13. [Medline].
Trovato MJ, Schwartz RA, Janniger CK. Tinea capitis: current concepts in clinical practice. Cutis. Feb 2006;77(2):93-9. [Medline].
Slowinska M, Rudnicka L, Schwartz RA, et al. Comma hairs: a dermatoscopic marker for tinea capitis: a rapid diagnostic method. J Am Acad Dermatol. Nov 2008;59(5 Suppl):S77-9. [Medline].
Gupta AK, Cooper EA, Bowen JE. Meta-analysis: griseofulvin efficacy in the treatment of tinea capitis. J Drugs Dermatol. Apr 2008;7(4):369-72. [Medline].
Fleece D, Gaughan JP, Aronoff SC. Griseofulvin versus terbinafine in the treatment of tinea capitis: a meta-analysis of randomized, clinical trials. Pediatrics. Nov 2004;114(5):1312-5. [Medline].
[Best Evidence] Gonzalez U, Seaton T, Bergus G, Jacobson J, Martinez-Monzon C. Systemic antifungal therapy for tinea capitis in children. Cochrane Database Syst Rev. Oct 17 2007;CD004685. [Medline].
Gupta AK, Hofstader SL, Adam P, Summerbell RC. Tinea capitis: an overview with emphasis on management. Pediatr Dermatol. May-Jun 1999;16(3):171-89. [Medline].
Koumantaki-Mathioudaki E, Devliotou-Panagiotidou D, Rallis E, et al. Is itraconazole the treatment of choice in Microsporum canis tinea capitis?. Drugs Exp Clin Res. 2005;31 Suppl:11-5. [Medline].
Friedlander SF, Aly R, Krafchik B, et al. Terbinafine in the treatment of Trichophyton tinea capitis: a randomized, double-blind, parallel-group, duration-finding study. Pediatrics. Apr 2002;109(4):602-7. [Medline].
Krafchik B, Pelletier J. An open study of tinea capitis in 50 children treated with a 2-week course of oral terbinafine. J Am Acad Dermatol. Jul 1999;41(1):60-3. [Medline].
Ghannoum MA, Wraith LA, Cai B, Nyirady J, Isham N. Susceptibility of dermatophyte isolates obtained from a large worldwide terbinafine tinea capitis clinical trial. Br J Dermatol. Sep 2008;159(3):711-3. [Medline].
[Best Evidence] Elewski BE, Caceres HW, DeLeon L, et al. Terbinafine hydrochloride oral granules versus oral griseofulvin suspension in children with tinea capitis: results of two randomized, investigator-blinded, multicenter, international, controlled trials. J Am Acad Dermatol. Jul 2008;59(1):41-54. [Medline].
Friedlander SF, Aly R, Krafchik B, et al. Terbinafine in the treatment of Trichophyton tinea capitis: a randomized, double-blind, parallel-group, duration-finding study. Pediatrics. Apr 2002;109(4):602-7. [Medline].
White JM, Higgins EM, Fuller LC. Screening for asymptomatic carriage of Trichophyton tonsurans in household contacts of patients with tinea capitis: results of 209 patients from South London. J Eur Acad Dermatol Venereol. Sep 2007;21(8):1061-4. [Medline].
Pomeranz AJ, Sabnis SS, McGrath GJ, Esterly NB. Asymptomatic dermatophyte carriers in the households of children with tinea capitis. Arch Pediatr Adolesc Med. May 1999;153(5):483-6. [Medline].
Williams JV, Honig PJ, McGinley KJ, Leyden JJ. Semiquantitative study of tinea capitis and the asymptomatic carrier state in inner-city school children. Pediatrics. Aug 1995;96(2 Pt 1):265-7. [Medline].
Arenas R, Toussaint S, Isa-Isa R. Kerion and dermatophytic granuloma. Mycological and histopathological findings in 19 children with inflammatory tinea capitis of the scalp. Int J Dermatol. Mar 2006;45(3):215-9. [Medline].
Elewski BE. Tinea capitis: a current perspective. J Am Acad Dermatol. Jan 2000;42(1 Pt 1):1-20; quiz 21-4. [Medline].
Elewski BE. Cutaneous fungal infections. In: Topics in Dermatology. Tokyo, Japan: Igaku-Shoin; 1992.
Elewski BE. Treatment of tinea capitis: beyond griseofulvin. J Am Acad Dermatol. Jun 1999;40(6 Pt 2):S27-30. [Medline].
Ergin S, Ergin C, Erdogan BS, Kaleli I, Evliyaoglu D. An experience from an outbreak of tinea capitis gladiatorum due to Trichophyton tonsurans. Clin Exp Dermatol. Mar 2006;31(2):212-4. [Medline].
Gorbach SL, Bartlett JG, Zorab R, Blacklow NR , eds. Dermatophyte infections of the hair, tinea capitis in fungal infections of the skin. In: Infectious Diseases. 2nd ed. Philadelphia, Pa: WB Saunders; 1997:1276-95.
Hay RJ. Clinical manifestations and management of superficial fungal infection in the compromised patient. In: Warnock DW, Richardson MD, eds. Fungal Infection in the Compromised Patient. New York, NY: John Wiley & Sons; 1992.
Kwon-Chung KJ, Bennett JE. Medical Mycology. Philadelphia, Pa: Lea & Febiger; 1992.
[Guideline] MacKenzie DWR, Loeffler W, Mantovani A, Fujikura T. Guidelines for the diagnosis, prevention and control of dermatophytosis in man and animals. World Health Organization WHO/CDS/VPH/86.67. 1986.
Mandell GL, Bennett JE, Dolin R, eds. Tinea capitis in dermatophytosis and other superficial mycosis. In: Principles and Practice of Infectious Disease. 1995. New York, NY: Churchill Livingstone; 2379-82.
Richardson MD, Warnock DW. Fungal Infection: Diagnosis and Management. London, England: Blackwell Scientific; 1993.
Rippon JW. Medical Mycology. 3rd ed. Philadelphia, Pa: WB Saunders; 1988.
Rippon JW. Tinea capitis in dermatophytosis and dermatomycosis. In: Medical Mycology, the Pathogenic Fungi and the Pathogenic Actinomycetes. Philadelphia, Pa: WB Saunders; 1988:186-96.
Rook A, Dawber R. Ringworm of the scalp. In: Infections and Infestations: Diseases of the Hair and Scalp. London, England: Blackwell Science; 1982:367-85.
Smith ML. Tinea capitis. Pediatr Ann. Feb 1996;25(2):101-5. [Medline].
Stein DH. Tineas--superficial dermatophyte infections. Pediatr Rev. Nov 1998;19(11):368-72. [Medline].
Yau-Chin Lu. Tinea capitis. In: Skin Diseases in Chinese. Taipei, Taiwan: Medicine Today; 1981:203-6.
Further Reading
Keywords
tinea capitis, ringworm of the scalp, tinea tonsurans, herpes tonsurans, superficial fungal infection of skin of scalp, superficial fungal infection of skin of eyebrows, superficial fungal infection of skin of eyelashes, superficial mycosis, dermatophytosis, scaly noninflamed dermatosis, scaly erythematous lesions, hair loss, alopecia, kerion, kerion celsi, parasitic infestation of skin, dermatophyte infection
Pityrosporum ovale, keratinophilic fungi, ectothrix infection, arthroconidia, endothrix infections, favus, tinea favosa, Trichophytonschoenleinii, Trichophyton violaceum, scutula, black dot tinea capitis, dermatophyte idiosyncratic reactions, id reactions
acute vesicular dermatitis, annular erythema, erythema nodosum, intradermal trichophytin, Trichophyton concentricum, anthropophilic fungi
