Do you test thyroid function in children with alopecia areata?

Thyroid Testing in Children with Alopecia Areata

Routine thyroid function testing is not recommended for all children with alopecia areata, as the increased frequency of autoimmune disease in patients with alopecia areata is probably insufficient to justify routine screening. 1

Current Evidence on Thyroid Testing in Alopecia Areata

The British Association of Dermatologists' guidelines clearly state that investigations are unnecessary in most cases of alopecia areata. When the diagnosis is in doubt, appropriate tests may include fungal culture, skin biopsy, serology for lupus erythematosus, or serology for syphilis, but routine thyroid screening is not recommended 1.

While some older research suggested routine thyroid function testing for all children with alopecia areata 2, more recent and higher-quality evidence supports a targeted approach to screening.

Risk-Based Approach to Thyroid Testing

A more selective approach to thyroid screening in children with alopecia areata is supported by recent research. Testing should be considered in children with:

• Personal history of Down syndrome
• Personal history of atopy
• Family history of thyroid disease
• Clinical findings suggestive of thyroid dysfunction (goiter, abnormal growth patterns)
• Symptoms of thyroid dysfunction 3

This targeted approach helps reduce unnecessary testing while identifying those at higher risk of thyroid abnormalities.

Thyroid Dysfunction in Children with Alopecia Areata

Research has found varying rates of thyroid abnormalities in children with alopecia areata:

• One study found 20% of children with alopecia areata had abnormal thyroid function tests 3
• Another study reported thyroid abnormalities in 24% of patients with new-onset alopecia areata 4
• Hypothyroidism (particularly Hashimoto's thyroiditis) is the most common thyroid abnormality found 3

Clinical Considerations

When evaluating children with alopecia areata:

1. Focus on obtaining a thorough history, including:

   • Family history of thyroid disease
   • Personal history of atopy or Down syndrome
   • Symptoms suggesting thyroid dysfunction (fatigue, weight changes, cold intolerance)

2. During physical examination, assess for:

   • Thyromegaly (enlarged thyroid)
   • Abnormal growth patterns
   • Signs of hypothyroidism (dry skin, delayed reflexes)
   • Signs of hyperthyroidism (tachycardia, tremor)

3. If testing is warranted, appropriate thyroid tests include:

   • Thyroid-stimulating hormone (TSH)
   • Free T4
   • Thyroid peroxidase antibodies (TPO-Ab)
   • Thyroglobulin antibodies (Tg-Ab)

Pitfalls to Avoid

1. Overscreening: Performing thyroid tests on all children with alopecia areata leads to unnecessary testing and potential false positives.

2. Misinterpreting results: Thyroid function tests may be misleading if performed during acute illness ("euthyroid sick syndrome") 5.

3. Overlooking high-risk patients: While routine screening isn't recommended, failing to test children with risk factors (Down syndrome, atopy, family history of thyroid disease) may miss important thyroid dysfunction.

4. Focusing only on thyroid: Remember that alopecia areata has multiple potential associations, and management should address the psychological impact, which can be significant, especially in children.

By following a targeted, risk-based approach to thyroid testing in children with alopecia areata, clinicians can provide appropriate care while avoiding unnecessary testing.