help me diagnose a ‘kagid’ (skin disease)

migi has this ‘kagid’ that started as like some blister then it becomes ‘kagid’ igbuto.
i noticed it monday
mark said it might be some allergy caused by water
i remembered then that saturday and sunday he played with water
so tuesday, i went to mercury drug then the pharmacist suggested to try ‘calmoseptine’ as treatment
so applied the cream, the wound would dry up
but after some time, mobasa na sad sya balik
right now, it looks like it gets worse
i stopped using the calmoseptine already
it really looks ‘lood,’ eeky, yucky!

any idea what kind of kagid is this?
treatment?
tenchu.