Alopecia Areata

Alopecia Areata (Also Discussed in Chapter 19: Hair and Scalp Disorders Resulting in Hair Loss)

Alopecia areata (AA) has an estimated lifetime risk of 1.7%, with a peak occurrence in childhood and adolescence. AA is a common autoimmune form of hair loss characterized by one or more focal patches of complete nonscarring alopecia that most often presents in childhood or adolescence.
AA is discussed in detail in Chapter 19: Hair and Scalp Disorders Resulting in Hair Loss, but the clinical features and its management in childhood will be discussed here.

The most common presentation in children is the sudden onset of a single well-circumscribed, localized patch of smooth alopecia (Fig. 9.1).
The preceding associated hair shedding may go unnoticed by the patient and/or parent.
Multiple alopecic patches, sometimes coalescing into larger geometric areas, may be present (Fig. 9.2) or; alopecic patches may be present elsewhere on the body such as the eyebrows (Fig. 9.3), eyelashes, beard, arms, or legs.
There is usually no associated redness or scaling.
In the initial active stage of the condition, peripheral hairs are short and thin, appear as “exclamation point hairs” (hairs with tapered ends) under dermoscopy, and are easily plucked from the scalp.
Initial hair regrowth often appears as white depigmented hairs.
Nails will show pitting in a grid-like pattern or trachyonychia in 10% to 20% of patients.

Progression to alopecia totalis (complete loss of scalp hair) occurs more commonly in children than adults and is estimated to occur in 5% of children with AA (Fig. 9.4).
Alopecia universalis occurs when there is complete loss of scalp and body hair and is the most severe form of alopecia areata.
The ophiasis pattern of alopecia areata describes a band-like distribution of hair loss along the hairline of the posterior occipital scalp and the inferior parietal scalp. This pattern occurring in <5% of children has a worse prognosis (see Fig. 19.9).

Poor Prognostic Factors in AA

Early age at onset (<2 years)
Coexisting atopy
Family history of autoimmune conditions
Presence of nail abnormalities

Diagnosis is made by recognizing the characteristic features on physical examination.
If in doubt, a skin biopsy showing peribulbar inflammation would be helpful at establishing the diagnosis.

Differential Diagnosis

Tinea Capitis

Presents as a scaly alopecic patch oftentimes black dots are visible.
KOH or fungal culture will be positive.

Trichotillomania (Compulsive Hair Pulling)

Seen most often in young girls.
Hairs tend to be broken at different lengths.
Occasionally, the alopecia has a telltale geometric shape (see discussion below and inChapter 19: Hair and Scalp Disorders Resulting in Hair Loss).

Congenital Triangular Alopecia (Triangular Temporal Alopecia [TTA])

Triangular-, oval-, or lancet-shaped alopecic patches typically located on the frontotemporal scalp (Fig. 9.5).
Nonprogressive, nonscarring alopecia in which mature hair follicles have been replaced with vellus-like hair follicles.
Despite the name, the alopecia more typically becomes apparent at 2 to 6 years of age when the surrounding hair becomes thicker.
TTA is typically sporadic but few familial occurrences have been reported.

Management

In the vast majority of children with AA, complete spontaneous regrowth is expected. Thus, therapy is often unnecessary.
Alopecia areata can become recurrent in up to 30% of patients.
Associated autoimmune disorders in affected children are quite rare, if a family history of other autoimmune disorders is elicited then an evaluation of autoimmune conditions, especially thyroiditis, may be indicated.
Treatment can help hasten regrowth but does not cure the condition and does not prevent new patches from developing.

Topical Treatments

First-line treatment in children is potent or superpotent topical corticosteroids such as clobetasol 0.05% cream or ointment with or without occlusion. Foams or solutions may be more practical.
Occlusion can be achieved with a shower cap.
If using superpotent topical steroids for a prolonged period on a large area of the scalp, it is important to watch closely for signs of cutaneous atrophy and systemic absorption.
Anthralin 1% cream works by a nonspecific immunostimulatory mechanism. Short contact therapy is used, initially applied to the affected area on the scalp and left on for 30 minutes then washed. The duration of contact is increased gradually to a maximum of 2 hours. The presence of a mild dermatitis is required for regrowth and can be treated with topical corticosteroids.
Anthralin can be irritating to the skin and can stain skin and clothes.
Immunotherapy with squaric acid induces an allergic contact dermatitis and works by driving away the perifollicular T cells allowing hairs to grow.
Squaric acid is useful in cases with large alopecic areas. Patients are sensitized to squaric acid (2%) with the application of the chemical on the inner right arm. Then 1 week later, a much lower percentage of squaric acid, usually 0.001%, is applied to the alopecic areas on the scalp and increasing concentrations are applied weekly until a mild low-grade dermatitis occurs. Therapy is continued until cosmetically acceptable regrowth occurs.
Excimer laser therapy (308 nm) targeted twice to three times per week to the alopecic area has been effective in some patients.
Topical minoxidil in a 2% or 5% concentration, scalp massage, heat, aloe vera, vitamins, hypnotherapy, oral psoralens combined with exposure to ultraviolet light in the A range (PUVA), narrow band UVB are other treatments that have varying success rates.

Intralesional Treatment

Older children and adolescents may tolerate intralesional injections with triamcinolone acetonide (5 mg/cc for scalp, 2.5 mg/cc for eyebrows).
Injections should be distributed evenly throughout the alopecic patch with a 30-gauge needle in aliquots of 0.1 mL, 1 cm apart; and administered every 4 to 6 weeks for best results.
The following pain-reducing techniques can help children tolerate the discomfort associated with the injections:
- Topical anesthetics such as EMLA cream (lidocaine 2.5% and prilocaine 2.5%) cream or LMX (lidocaine 4% cream) applied to area to be injected 30 minutes prior to treatment.
- Gebauer's Ethyl Chloride spray, a skin coolant, sprayed directly on the area to be injected immediately prior to the injection provides instant temporary anesthesia.
- Buzzy is a palm-sized high-frequency vibration device that is placed on the skin next to the injection site and decreases the perception of pain.

Systemic Treatments

High-dose pulse therapy with PO prednisone or IV methylprednisolone is reserved for patients with severe (>50% scalp hair) and recurrent disease.
Corticosteroid pulses are more likely to be effective in patients with a short disease duration (6 months), younger age at disease onset (<10 years), and multifocal disease (as opposed to severe, diffuse variants).
Relapse rate is high.
Cyclosporine and methotrexate have been tried with variable success. Treatment with the biologics such as adalimumab, alefacept, etanercept, and infliximab, has been uniformly disappointing.

Helpful Hints

The vast majority of children have mild or moderate alopecia areata involving <50% of scalp hair.
Children using superpotent topical steroids under occlusion may absorb sufficient corticosteroids to have systemic effects; absorption can be evaluated with an 8 am cortisol level.
Locks of Love is a nonprofit organization that provides hair prostheses to children under the age of 18 years (www.locksoflove.org).
The National Alopecia Areata Foundation (www.alopeciaareata.com) is a national support group that can be a valuable resource for families.

section name header

Basics ⬇

Clinical Manifestations ⬆ ⬇

Clinical Variant ⬆ ⬇

Diagnosis ⬆