Unusual and rare presentations of tinea capitis can sometimes mimic cicatricial alopecia. According to one expert, it is important to consider all possible diagnoses and especially rule out a fungal scalp disease, no matter how suspicious the clinical presentation may be.
According to one expert, it is crucial to perform fungal cultures, and possibly perform a scalp biopsy, in order to differentiate tinea capitis from cicatricial alopecia.
"Sometimes, it is difficult to make a diagnosis of tinea capitis, especially when patients present with highly inflammatory suppurating nodules resulting in profuse hair loss.
Dr. Mirmirani recently received two pediatric referrals who were suspected of having cicatricial alopecia because of the unusual clinical picture.
Patient one had a history of atopic dermatitis and presented with an itchy plaque with hair loss on the scalp. At initial assessment, the patient was given oral antibiotics and oral griseofulvin; however, these medications were soon stopped due to a presumed "allergic reaction," upon which he received oral corticosteroids. Although the rash resolved, the hair loss rapidly progressed to 25 percent of the scalp.
Patient two also had a history of atopic dermatitis and developed a facial and scalp rash thought to be caused by poison oak. At initial assessment, the patient was given topical and oral corticosteroids upon which she developed a large 7 cm diameter patch of hair loss on the scalp. She subsequently received oral griseofulvin, which proved to be only minimally effective.
Upon referral to Dr. Mirmirani, the clinical examination of patient one revealed no lymphadenopathy, minimal scalp inflammation, no "black dots" and apparent loss of follicular markings.
Fungal culture showed T. tonsurans, and the patient received treatment with topical Lamisil (terbinafine, Novartis), Nizoral (ketoconazole, McNeil) shampoo and oral terbinafine, 250 mg for two months, which led to complete hair regrowth.
Fungal culture demonstrated T. mentagrophytes in patient two, and the patient received treatment with oral Lamisil, which led to resolution of symptoms with full hair regrowth.
"We can see from these two cases that, clearly, patients with atopic dermatitis or an atopic diathesis have an altered immune system that can change the rules in terms of 'typical' presentations of cutaneous disease," Dr. Mirmirani says.
"Sometimes, cortisone is the proper treatment in very inflammatory cases of tinea capitis; however, this case underscores the importance that clinicians should expect the unexpected and always perform fungal cultures to rule out the diagnosis," Dr. Mirmirani tells Dermatology Times.
According to Dr. Mirmirani, the aberrant immune response seen here may have been due to the use of oral corticosteroids and/or could have been a manifestation of cutaneous immune dysregulation in these patients with atopic dermatitis.
Typically, tinea capitis presents as a patch area of hair loss on the scalp, often with black dots, which represent the breakage of hair shafts due to the fungus. There is scaling of the scalp, and patients have significant lymphadenopathy.
However, some patients can just present with mild scaling of the scalp (the carriers), spreading the fungus along with very few symptoms themselves.
"Cicatricial alopecia in children is quite rare, and if someone is entertaining that diagnosis, they should highly consider other more likely causes of hair loss in children, such as tinea capitis. Therefore, KOH examinations should be done, and if negative, fungal cultures should be sent," Dr. Mirmirani says.
Disclosure: Dr. Mirmirani reports no relevant financial disclosures.