Hypopigmented Patches Around Mouth in Infants
Most Likely Diagnosis
Pityriasis alba is the most common cause of hypopigmented patches around the mouth in infants, presenting as ill-defined, scaly patches of hypomelanosis on the cheeks and perioral areas, particularly in children with atopic diathesis. 1, 2
Differential Diagnoses
Primary Considerations
Pityriasis alba: Ill-defined, scaly hypopigmented patches on face (especially cheeks and perioral area), strongly associated with atopy and dry skin 3, 1, 2
Vitiligo: Complete depigmentation (not hypopigmentation) with periorificial distribution around mouth, eyes, and other body orifices; patches are well-demarcated and chalk-white 4, 1, 5
Postinflammatory hypopigmentation: History of preceding inflammation, dermatitis, or injury; typically resolves spontaneously within weeks to months 6, 7
Nevus depigmentosus: Congenital, stable leukoderma present from birth (not acquired); does not progress 1, 7
Less Common but Important
Peutz-Jeghers syndrome: Dark brown or blue-brown pigmented macules (hyperpigmentation, not hypopigmentation) on vermilion border of lips and buccal mucosa appearing in infancy; associated with gastrointestinal hamartomatous polyps 4
Tinea versicolor: Favors upper trunk in adolescents rather than perioral area in infants; KOH preparation shows hyphae and yeast forms 1
Recommended Work-Up
Clinical Examination
Wood's light examination: Accentuates hypopigmentation in pityriasis alba (no fluorescence) and helps delineate complete depigmentation in vitiligo 4, 3
Assess for atopic features: Look for xerosis, eczema, or other signs of atopic dermatitis suggesting pityriasis alba 3, 2
Evaluate pigment loss: Partial hypopigmentation suggests pityriasis alba; complete chalk-white depigmentation indicates vitiligo 1
Check distribution pattern: Ill-defined patches on cheeks favor pityriasis alba; well-demarcated periorificial patches suggest vitiligo 1, 5
Laboratory Testing (If Vitiligo Suspected)
Thyroid function tests and thyroid autoantibodies: Autoimmune thyroid disease occurs in approximately 34% of vitiligo patients and is the most common association 8, 5
Consider referral to dermatology: For atypical presentations or diagnostic uncertainty 4, 3
First-Line Management
For Pityriasis Alba (Most Likely)
Emollients and moisturizers: Address underlying dry skin and atopic features as first-line therapy 3, 2
Mild-to-moderate potency topical corticosteroids: Limited duration to avoid skin atrophy 3
Potent topical steroids: Trial period of no more than 2 months maximum due to risk of skin atrophy 3
Topical calcineurin inhibitors (pimecrolimus or tacrolimus): Alternative with better short-term safety profile, particularly suitable for facial application 4, 3
Patient education: Sun exposure exacerbates contrast between normal and lesional skin; proper skin care and hygiene promote resolution 2
For Vitiligo (If Diagnosed)
Potent or very potent topical steroids: Trial period of no more than 2 months in children under 18 years 4
Topical calcineurin inhibitors: Preferred alternative to highly potent steroids due to better safety profile on facial skin 4
Thyroid screening: Essential given 34% prevalence of autoimmune thyroid disease 8, 5
Psychological support: Offer counseling to parents and child given significant quality of life impact 4, 8
Common Pitfalls to Avoid
Extending potent topical steroid use beyond 2 months: Causes skin atrophy, particularly problematic on facial skin 4, 3
Failing to screen for thyroid disease in vitiligo: Misses treatable autoimmune thyroid disease present in one-third of patients 8, 5
Confusing hypopigmentation with depigmentation: Pityriasis alba shows partial pigment loss; vitiligo shows complete chalk-white depigmentation 1
Overlooking atopic features: Missing the atopic diathesis connection delays appropriate management of pityriasis alba 3, 2
Dismissing psychological impact: Visible facial lesions significantly affect quality of life in children and families, warranting psychological support 4, 8