History

Fact Explanation
Initially appear as erythematous scaly ring like papule on scalp Tinea capitis is a superficial dermatophyte fungal infection involving the skin of scalp, eyebrows and eye lashes. It is caused by organisms of genera Trichophyton and Microsporum. Fungi of human sources (anthrophilic organisms) cause balding and scaly areas with minimal inflammation. [1],[2],[3],[4]
Boggy swelling Due to acute severe inflammation, with pus infiltration and crust formation results in a boggy swelling. This is known as a 'kerion'. Fungi coming from animal sources (zoophilic fungi) induce a more intense inflammation than those from person to person. [1],[2]
Alopecia Areas of hair loss occur due to breakage of infected hair shafts. Dermatophyte infection can be divided into endothrix, which refers to spread within the hair shaft and ectothrix, which refers to spread outside the hair shaft. In endothrix infected hairs break off sharply at the follicular orifice.This is associated with 'kerion' formation. In an ectothrix infection destruction of cuticle occurs. [1],[2],[3],[4]
Pruritis Most of the patients complain of pruritus and this ranges from mild to intense itching. [1],[2]
Contact history Tinea capitis is a contagious and communicable fungal infection. Therefore contact history with infected family member or regular sharing of hats, combs,hair brushes, towels and pillows or animal contact may be positive in the history. Overcrowding and poor social conditions are also risk factors. [3],[4]
Common among pre adolescents In puberty the sebum content of skin surface increases. Sebum which is rich in lipids provide a suitable media for growth of causative organisms. [3]
References
  1. WELLER, Richard P.J.B. HUNTER, John A.A. SAVIN, John A. and DAHL, Mark V. Clinical Dermatology. 4th Ed. Blackwell publishing. 2008, 248-252.
  2. MARKS, Ronald. ROXBURGH'S Common Skin Diseases. 17th Ed. Arnold Publishers. 2003, 39-43.
  3. MICHAELS, Brent D. and DEL ROSSO, James Q. Tinea Capitis in Infants. The Journal of Clinical and Aesthetic Dermatology. Feb 2012; 5(2): 49–59. [Viewed on 31-03-2014] Available from:http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3315884/
  4. KUMAR, Parveen and CLARK, Michael. KUMAR & CLARK'S Clinical Medicine. 8th Ed. ELSEVIER. 2012,1200-1201.

Examination

Fact Explanation
Single or numerous erythematous scaly circular ring like papule on scalp. Tinea capitis is a superficial dermatophyte fungal infection involving the skin of scalp, eyebrows and eye lashes. [1],[2],[3]
Inflammed crusts and exudate. As the immune response increases a few pustules appear and an exudate may be present. At worst, a 'kerion' develops resulting in a boggy mass. [1],[2],[4]
Patchy alopecia. Areas of hairloss occur due to breakage of infected hair shafts a few millimeters above the skin of the scalp. There may be black dots that indicate intrafollicular hair shafts that have broken off as the shaft protrudes above the scalp surface. [1],[2], [3], [4]
Cervical lympadenopathy May be positive in patients with a severe acute inflammation associated with 'kerion' formation [3].
Widespread papulo pustular rash on the trunk. Extensive infection is occasionally accompanied by a widespread papulo pustular rash on the trunk. This is known as an 'id reaction'. This is probably due to the host immune response to fungus. It resolves when fungal infection is treated. [4]
References
  1. WELLER, Richard P.J.B. HUNTER, John A.A. SAVIN, John A. and DAHL, Mark V. Clinical Dermatology. 4th Ed. Blackwell publishing. 2008, 248-252.
  2. MARKS, Ronald. ROXBURGH'S Common Skin Diseases. 17th Ed. Arnold Publishers. 2003, 39-43.
  3. MICHAELS, Brent D. and DEL ROSSO, James Q. Tinea Capitis in Infants. The Journal of Clinical and Aesthetic Dermatology. Feb 2012; 5(2): 49–59. [Viewed on 31-03-2014] Available from:http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3315884/
  4. KUMAR, Parveen and CLARK, Michael. KUMAR & CLARK'S Clinical Medicine. 8th Ed. ELSEVIER. 2012,1200-1201.

Differential Diagnoses

Fact Explanation
Alopecia areata A typical patch of hair loss is notably not inflamed, with no scaling, but presence of empty hair follicles can be noted. Pathognomic 'exclamation-mark' hairs may be seen around the edge of enlarging areas. They are broken off about 4mm from the scalp, and are narrowed and less pigmented proximally. Usually associated with autoimmune disorders. [1], [2],[3]
Plaque psoriasis It is characterized by pinkish red scaly plaques, with silver scales. Extensor surfaces such as knees and elbows, lower back, ears and scalp are also commonly involved. [1],[2],[3]
Seborrhic dermatitis Scalp involvement is more diffuse and less lumpy. Intervening areas of scalp skin are unusual. Plaques are not so sharply marginated. [1]
Impetigo A thin walled flaccid clear blister forms and may become pustular before rupturing to cause exudation and yellowish honey like crusting. Lesions are often multiple and found particularly around the face. [1]
Carbuncle A group of adjacent hair follicles becomes deeply infected, leading to a swollen painful suppurating area with discharging pus from several points. [1]
Abscess An abscess is a localized collection of pus in a cavity more than 1cm diameter. Ruptured abscesses on scalp skin may mimic kerion. [1]
Trichotillomania Is a compulsive disorder of hair pulling. The bald areas do not show the exclamation mark hair of alopecia areata or the scaling and inflammation of tinea capitis. [1]
References
  1. WELLER, Richard P.J.B. HUNTER, John A.A. SAVIN, John A. and DAHL, Mark V. Clinical Dermatology. 4th Ed. Blackwell publishing. 2008, 36, 54-70, 179-181, 221-228, 248-252, 346-347.
  2. MARKS, Ronald. ROXBURGH'S Common Skin Diseases. 17th Ed. Arnold Publishers. 2003, 39-43, 128-142, 271.
  3. KUMAR, Parveen and CLARK, Michael. KUMAR & CLARK'S Clinical Medicine. 8th Ed. ELSEVIER. 2012,1200-1203, 1207-1210, 1232.

Investigations - for Diagnosis

Fact Explanation
Wood's light examination Utilizes a ultra violet light to observe the scalp skin closely. Usually gives a green fluorescence glow in Microsporum audouini and M.canis infections.This method is useful for screening children in institutions where outbreaks of tinia capitis can occur, however the most common fungus causing tinea capitis - Trychophyton tonsurans does not fluorescence. [1],[2]
Light microscopic examination of skin scrapings. The scrapings should be taken from the scaly margin of the lesion, with small curette or a scalpel blade. Specimens are prepared with Potassium hydroxide. Branching hyphae can be seen on light microscopic examination. Hyphae may also be seen within the cleared hair shaft and spores may be seen around it. [1],[2]
Culture Culture should be carried out in a mycology or bacteriology laboratory. A transport medium is not necessary. Specimens can be sent in folded black paper or in a dry petri dish. Culture results may take up to 1 month. [1],[2]
References
  1. WELLER, Richard P.J.B. HUNTER, John A.A. SAVIN, John A. and DAHL, Mark V. Clinical Dermatology. 4th Ed. Blackwell publishing. 2008, 248-252.
  2. MARKS, Ronald. ROXBURGH'S Common Skin Diseases. 17th Ed. Arnold Publishers. 2003, 39-43.

Management - General Measures

Fact Explanation
Patient education and counselling Inform the patient that this is a common superficial fungal infection which can be treated successfully with local application of anti fungals. [1],[2],[3]
Education on hygiene This is a contagious condition. Patients should be advised not to share their personal combs, hair brushes, hats, towels and pillows to prevent recurrences. Regular bathing and wearing of clean dry clothes can prevent many superficial fungal infections. [1],[2]
References
  1. WELLER, Richard P.J.B. HUNTER, John A.A. SAVIN, John A. and DAHL, Mark V. Clinical Dermatology. 4th Ed. Blackwell publishing. 2008, 248-252.
  2. MARKS, Ronald. ROXBURGH'S Common Skin Diseases. 17th Ed. Arnold Publishers. 2003, 39-43.
  3. KUMAR, Parveen and CLARK, Michael. KUMAR & CLARK'S Clinical Medicine. 8th Ed. ELSEVIER. 2012,1200-1201.

Management - Specific Treatments

Fact Explanation
Topical Imidazole preparations This is for minor lesions and is considered ineffective in tinea capitis. [1]
Griseofulvin Was the drug of choice for many years for tinea capitis. It has proven to be safe drug. (500mg b.d for 2-6 weeks) But treatment may have to be stopped if there are persistent headaches, nausea, vomiting or skin eruptions. It prevents fungal growth by inhibiting mitosis. The drug should not be given in pregnancy or in patients with liver failure or porphyria. It interacts with coumarin anticoagulants, therefore the dosage of may have to be increased. [1],[2],[3],[4]
Terbinafine Acts by inhibiting ergosterol synthesis in fungi by inhibition of squalene epoxidase which is a part of the fungal cell membrane synthesis pathway. It is fungicidal. It cures dermatophyte infections more quickly and more reliably than griseofulvin. For tinea capitis administration of 250mg daily for 4 week is effective. [1],[2],[3]
Itraconazole This is now preferred over Ketoconazole, which may cause liver damage. Fungistatic rather than fungicidal. It interferes with cytochrome P-450 enzyme system of the liver. Given as 100mg daily for 2-6 weeks. Serious side effects are uncommon but interactions with other drugs must be avoided. [1],[2],[3],[4]
Ketoconazole The drug should be reserved for patients with severe and resistant disease because of the possibility of serious hepatotoxicity and occurrence of other side effects such as rashes, thrombocytopenia and gastrointestinal disturbances. [1],[2],[3],[4]
References
  1. WELLER, Richard P.J.B. HUNTER, John A.A. SAVIN, John A. and DAHL, Mark V. Clinical Dermatology. 4th Ed. Blackwell publishing. 2008, 248-252.
  2. MARKS, Ronald. ROXBURGH'S Common Skin Diseases. 17th Ed. Arnold Publishers. 2003, 39-43.
  3. KUMAR, Parveen and CLARK, Michael. KUMAR & CLARK'S Clinical Medicine. 8th Ed. ELSEVIER. 2012,1200-1201.
  4. BENNET, P.N.and BROWN, M.J. CLINICAL PHARMACOLOGY. 9th Ed. CHURCHILL LIVINGSTONE. 2003, 263-267.