Dr. Greene’s Answer:
I bet your 14-month-old is adorable. White patches on the face at that age are quite common. Sounds like you’ve done your homework about them!
Pityriasis alba (which is Latin for white, scaly patches), is the most common cause. Children develop uneven round or oval patches, especially after sun exposure. The patches are dry with very fine scales. They are most common on the face (cheeks), neck, upper trunk, and upper arms of children 3 to 16 years old.
These are completely benign, similar to a mild form of eczema. They are most common in children with dry skin. The involved patches don’t darken with sun exposure the way the surrounding skin does. Treatment involves daily lubrication with a good moisturizer such as Aquaphor, especially whenever the skin gets wet. Sometimes mild topical steroid creams help (1% hydrocortisone).
Even with no treatment at all, the spots will disappear on their own — although it may take months to years. Some people get pityriasis alba every summer during childhood. Even then, the pigmentation will eventually end up normal.
If this doesn’t sound like your son, tinea versicolor is another common cause — though it is usually found in older children. This is similar to athlete’s foot and needs an antifungal medication or a selenium shampoo for treatment.
With either pityriasis alba or tinea versicolor, even when the condition is effectively treated, the white patches will remain for a while. At least several weeks must pass for the newly healthy skin to adjust its color to the amount of ongoing sunlight exposure so that it will match the surrounding skin.
At your son’s upcoming 15-month-old well child exam, it would be wise to ask the doctor about the patches, just to be sure what they are.
References and Resources
Miazek N, et al. Pityriasis Alba–Common Disease, Enigmatic Entity: Up-to-Date Review of the Literature. Pediatr Dermatol. 2015: ;32(6):786-91.