Thank you for your query.
Since how long have you been noticing the boils/cyst
and do they hurt your son when you touch them. If these are of recent origin and painful to touch then you need to consult your doctor. The skin is probably getting infected and may need treatment depending on the cause.
The prolonged used of pampers without change may be affecting the skin. It can either be a bacterial or even a fungal infection
I hope I have responded to your query to your satisfaction.
Wishing your son all the best.