Our 20 months old son has some black spots on his skin. They occur randomly and vanish in 2 or 3 weeks. He started getting them from 11 months of age or so. If he gets a mosquito bite, the skin turns reddish and swollen a bit and swelling vanishes in three hours of time, but he gets a mark there. Sometimes black spots occur even without mosquito bites. He gets them usually after he wakes up from his sleep.
The black spots do not occur in his body but on his face, hands or legs i.e., the area which is exposed outside. At times he has itching sensation. The black spots didn't come in summer season. But he gets them in winter and during weather change periods.
Recently he had three pustules, he got pus from them as he itched them. It got cured in a week. But the marks are just there in his legs.
We have observed the following syndromes for possible causes.
a) type of dresses he wears, any new dress
b) carpets, bed sheets.
None of them are the reasons. We keep him very clean, nails are cut regularly.
What is the reason of these black spots? How can we avoid them? Does he have a very sensitive skin?
Is it something internal? Is it an auto-treatment type ? If so, when will it get cured?
Is there any special food to boost his immune system to avoid these rashes?