What is the treatment for white patches on a child's face, possibly due to conditions like pityriasis versicolor, vitiligo, or eczema?

White Patches on a Child's Face: Diagnostic and Treatment Approach

Initial Diagnostic Evaluation

The diagnosis of white patches on a child's face should be based on clinical examination with Wood's light evaluation, which is particularly useful in fair-skinned patients, and serial photographs to monitor changes over time. 1

The most common causes of white patches on children's faces include:

• Pityriasis alba - the most common cause, presenting as hypopigmented patches often with fine scale, typically in atopic children 2, 1
• Tinea versicolor (pityriasis versicolor) - hypopigmented or hyperpigmented scaly patches, more common in warm climates 3, 4, 5
• Vitiligo - well-demarcated depigmented (not hypopigmented) patches with symmetrical distribution 2, 1
• Atopic dermatitis - may present with associated hypopigmentation, pruritus, and typical eczematous features 2

Key Diagnostic Features

• Visual inspection and palpation should assess for scale, texture, and distribution patterns 1
• Wood's light examination enhances visualization of hypopigmented lesions, especially in lighter skin types 1, 6
• Dermoscopy can aid in clinical assessment 1
• For multiple hypopigmented macules with irregular borders, early referral to pediatric dermatology is recommended 1
• For solitary small or medium lesions without concerning features, referral can be delayed or managed in primary care 1

Treatment Based on Specific Diagnosis

Pityriasis Alba

Bland emollients applied regularly are the primary treatment to address xerosis and reduce itching in children with pityriasis alba. 1

• This condition is self-limited and often requires only reassurance and moisturization 1
• The hypopigmentation typically resolves gradually over months to years 2

Tinea Versicolor (Pityriasis Versicolor)

Topical treatments should be the first-line therapeutic option in children due to their favorable safety profile. 3

• Ketoconazole cream 2% applied once daily for two weeks is FDA-approved and effective 4
• Ketoconazole shampoo can be used as an alternative topical option 7
• Selenium sulfide and zinc pyrithione shampoo are additional topical alternatives 7
• Treatment duration is typically two weeks for tinea versicolor 4
• Proper cleaning of combs and brushes is essential to avoid reinfection 3
• Prophylactic treatment regimens may be necessary to prevent recurrence 7

Vitiligo

For children with vitiligo, topical calcineurin inhibitors are preferred over potent steroids for safety reasons. 1

Initial Management Steps:

• Perform thyroid function tests, including anti-thyroglobulin antibodies, due to high prevalence of autoimmune thyroid disease 1, 6
• Document extent with serial photographs for monitoring progression 1, 6
• Assessment of skin type is useful in initial examination 6

Treatment Options:

• Topical calcineurin inhibitors (tacrolimus, pimecrolimus) are preferred in children under 18 years 1
• If topical steroids are used, limit potent or very potent formulations to no more than 2 months due to risk of skin atrophy 2, 1
• Narrowband UVB phototherapy should be reserved for widespread disease or significant quality of life impact, monitored with serial photographs every 2-3 months 2, 1
• Safety limits for NB-UVB are more stringent than for psoriasis, with an arbitrary limit of 200 treatments for skin types I-III 2
• Oral corticosteroids should be avoided due to unacceptable risk of side-effects in children 2, 1

Special Considerations:

• For children with skin types I-II and limited disease, camouflage cosmetics and sunscreens may be appropriate initial management without active treatment 2, 1
• Psychological assessment and support should be offered to children and parents, as pigmentation disorders can significantly impact quality of life 2, 1

Atopic Dermatitis with Hypopigmentation

Diagnosis should be based on essential features: pruritus, typical eczematous morphology with age-specific patterns, and chronic or relapsing history. 2

• Pityriasis alba is listed as an associated feature of atopic dermatitis 2
• Treatment follows standard atopic dermatitis management with topical emollients and appropriate anti-inflammatory therapy 2

Common Pitfalls to Avoid

• Do not use potent topical steroids on the face for extended periods - limit to 2 months maximum to prevent skin atrophy 2, 1
• Do not prescribe oral corticosteroids for vitiligo in children - unacceptable side-effect profile 2, 1
• Do not overlook thyroid screening in vitiligo patients - autoimmune thyroid disease is common 1, 6
• Do not forget to address psychological impact - white patches on the face can significantly affect quality of life in children 2, 1
• Ensure proper follow-up for tinea versicolor - recurrence is common without prophylactic measures 3, 7