What is the recommended initial lab workup for pediatric vitiligo?

Initial Laboratory Workup for Pediatric Vitiligo

A thyroid function test should be considered as the primary laboratory workup for pediatric vitiligo patients due to the high prevalence of autoimmune thyroid disease in this population. 1

Diagnostic Approach

• Where vitiligo presents with classical symmetrical patterns, diagnosis is straightforward and can be made in primary care, but atypical presentations may require referral to a dermatologist 1
• Assessment of skin type is useful in the initial examination, along with photographs to document the extent of disease 1
• Wood's light examination can be helpful in monitoring response to therapy, particularly in fair-skinned patients 1

Laboratory Investigations

Primary Laboratory Test

• Thyroid function tests should be considered for all pediatric vitiligo patients, including:
  • Free triiodothyronine (T3)
  • Free thyroxine (T4)
  • Thyroid-stimulating hormone (TSH)
  • Anti-thyroid peroxidase antibodies
  • Anti-thyroglobulin antibodies 1, 2, 3

Rationale for Thyroid Testing

• Children with vitiligo show an increased incidence of autoimmune thyroiditis 2
• Vitiligo typically appears before the development of thyroid disease, making screening particularly valuable for early detection 3
• The prevalence of thyroid dysfunction in pediatric vitiligo patients ranges from 5.9% to 11.8% according to different studies 2, 3, 4

Risk Stratification

• Higher risk patients who particularly benefit from thyroid screening include:

  • Female patients (significant association between autoimmune thyroiditis and female sex) 2
  • Patients with longer disease duration 2
  • Patients with generalized/vulgaris-type (nonsegmental) vitiligo 3

• Lower risk patients:

  • Patients with segmental vitiligo show significantly lower rates of thyroid abnormalities 3, 4

Follow-up Recommendations

• Annual screening for thyroid function and antithyroid antibodies is recommended, especially for:
  • Girls with vitiligo
  • Patients with generalized/vulgaris-type vitiligo 2

Clinical Pearls and Pitfalls

• While overt hypothyroidism or hyperthyroidism may not be initially detected, subclinical thyroid dysfunction can be present 2, 4
• Family history of thyroid disorders or autoimmune diseases should be noted, as 42% of pediatric vitiligo patients may report at least one family member with such conditions 2
• The most common type of vitiligo in children is vitiligo vulgaris, with the face being the most commonly involved site 5, 4

By following this laboratory workup approach, clinicians can help in the early diagnosis and management of autoimmune thyroiditis in pediatric vitiligo patients, potentially improving long-term outcomes.