Overview
Definition:
Alopecia areata (AA) is a common, non-scarring, autoimmune disorder characterized by patchy hair loss on the scalp and/or other hair-bearing areas
It results from a cell-mediated autoimmune attack against hair follicles
In children, it can present with significant psychosocial impact.
Epidemiology:
AA affects approximately 0.1% to 0.3% of the pediatric population
It can occur at any age, with a bimodal peak in incidence between 20-30 years and 40-50 years, though pediatric onset is not uncommon
There is no known gender predilection
Family history of autoimmune diseases is frequently reported.
Clinical Significance:
Pediatric AA poses a significant challenge due to its unpredictable course, potential for spontaneous remission, and substantial psychosocial distress in affected children and their families
Understanding the nuances of topical and systemic therapies is crucial for effective management and improving quality of life, and is a key area for DNB and NEET SS examinations.
Clinical Presentation
Symptoms:
Well-demarcated, circular or oval patches of hair loss
Usually asymptomatic, but may be associated with mild itching or tingling prior to hair loss
Ophiasis pattern (hair loss along the temporal and occipital hairline) and alopecia totalis (total scalp hair loss) or alopecia universalis (total body hair loss) are more severe forms
Nail changes like pitting, ridging, or onycholysis may be present.
Signs:
Smooth, bald patches of skin, typically without erythema or scaling
Exclamation mark hairs (short, broken hairs narrower at the base) may be seen on close examination
Widely spaced hairs at the periphery of active lesions
Presence of dystrophic nails is a significant finding.
Diagnostic Criteria:
Diagnosis is primarily clinical, based on the characteristic appearance of the alopecia
Definitive diagnosis can be confirmed with scalp biopsy showing perifollicular lymphocytic infiltrate, especially in uncertain cases or to rule out other causes
A detailed family history for autoimmune diseases and atopy is important.
Diagnostic Approach
History Taking:
Onset and progression of hair loss
Site and extent of involvement
Previous episodes and treatments
Family history of alopecia, autoimmune disorders (thyroiditis, vitiligo, diabetes mellitus), or atopy
Any associated symptoms like itching or pain
Impact on child's psychosocial well-being.
Physical Examination:
Careful examination of the scalp for characteristic patches, hair stumps (exclamation mark hairs), and evidence of inflammation
Assessment for nail abnormalities
Examination of other hair-bearing areas (eyebrows, eyelashes, beard, axillae, pubic areas)
General physical examination to screen for signs of associated autoimmune diseases.
Investigations:
Scalp biopsy for histopathology is indicated in atypical presentations or to confirm diagnosis in ambiguous cases
It typically reveals a perifollicular lymphocytic infiltrate, with eosinophils and neutrophils at the infundibulum, and potential follicular miniaturization
Blood tests (CBC, thyroid function tests, autoantibodies like ANA, anti-TPO) may be considered to rule out associated autoimmune conditions, but are not routine for diagnosing AA itself.
Differential Diagnosis:
Tinea capitis (fungal infection of the scalp, often with scaling and inflammation), traction alopecia (hair loss at the hairline due to prolonged tension), trichotillomania (self-induced hair pulling, often with irregular hair lengths and broken hairs), telogen effluvium (diffuse hair shedding), androgenetic alopecia (patterned hair loss in older children/adolescents), and other scarring alopecias.
Management
Initial Management:
Reassurance and education for the child and parents regarding the benign nature of AA, its autoimmune origin, and the possibility of spontaneous remission
Discussing the psychosocial impact and offering support resources
Explanation of treatment goals and potential side effects.
Topical Therapies:
Corticosteroids: Potent topical corticosteroids (e.g., clobetasol propionate, betamethasone valerate) applied daily or on alternate days
Minoxidil: 2% or 5% solution/foam applied twice daily to stimulate hair regrowth
Anthralin: 0.5% to 1% cream/ointment applied for short contact therapy (minutes to hours) and then washed off, to induce a localized inflammatory response.
Systemic Therapies:
Corticosteroids: Oral corticosteroids (e.g., prednisone) for severe, rapidly progressive, or widespread disease
Typically started at a high dose and tapered slowly
Methotrexate: An immunosuppressant, often used for more severe or refractory cases, administered weekly
Immunosuppressants: Other agents like cyclosporine or azathioprine are less commonly used in pediatrics due to side effect profiles and are reserved for refractory, life-altering disease
JAK inhibitors: Emerging therapies, under investigation for severe pediatric AA, targeting specific inflammatory pathways.
Supportive Care:
Psychological support and counseling for affected children and families to address body image issues and social anxiety
Patient support groups can be beneficial
Sun protection for bald areas
Management of nail involvement, if present
Regular follow-up to monitor treatment response and potential side effects.
Complications
Early Complications:
Psychosocial distress, anxiety, depression, social withdrawal, and bullying
Development of more extensive disease patterns (alopecia totalis/universalis).
Late Complications:
Chronic or recurrent disease, impacting long-term self-esteem and social functioning
Association with other autoimmune diseases like thyroiditis, vitiligo, and type 1 diabetes mellitus, especially in those with positive family history or more extensive disease.
Prevention Strategies:
Early diagnosis and initiation of appropriate treatment can help manage extent of hair loss
Addressing psychosocial issues promptly is key to prevent long-term psychological sequelae
Careful monitoring for associated autoimmune conditions.
Prognosis
Factors Affecting Prognosis:
Younger age of onset, extensive disease at presentation, presence of nail changes, family history of autoimmune disease, and ophiasis pattern are associated with a poorer prognosis and higher likelihood of recurrence
Spontaneous remission is common, especially in milder cases.
Outcomes:
Complete regrowth can occur in many children, particularly with milder forms
However, AA can be chronic and relapsing
Treatment aims to promote hair regrowth and improve quality of life, but complete and permanent remission is not always achievable
Topical treatments are often effective for milder cases, while systemic therapies are reserved for more severe or refractory disease.
Follow Up:
Regular follow-up appointments (e.g., every 3-6 months) are necessary to assess treatment efficacy, monitor for side effects, and manage psychosocial aspects
The frequency of follow-up may increase during active treatment phases and decrease once remission is achieved
Long-term monitoring is recommended due to the relapsing nature of AA.
Key Points
Exam Focus:
Understanding the autoimmune basis of AA, differentiating it from tinea capitis, and knowing the indications and general mechanisms of topical (corticosteroids, minoxidil, anthralin) and systemic (oral steroids, methotrexate) therapies in pediatric patients
Recognize the significant psychosocial impact.
Clinical Pearls:
Always inquire about nail changes and family history of autoimmune diseases in suspected cases of pediatric AA
Explain to parents that while AA is often benign and may resolve spontaneously, treatment can help manage the extent and duration
Prioritize psychosocial support alongside medical management.
Common Mistakes:
Over-treating mild cases with aggressive systemic agents, failing to address psychosocial distress adequately, misdiagnosing AA as tinea capitis without proper investigation, and not considering associated autoimmune conditions, especially in children with more extensive or recalcitrant disease.