you discribe is less likely to be allergy
to drug .it can be scabies
because both of you have it.If the itching &rash is specially in body folds,it's definately scabies.
For this apply Ascabiol lotion to compleate body below neck after bath- for 5 days at a strech.lotion to be kept out of reach of children.it is poisonus, so should not be applied to face/mouth
These days avoid skin to skin contact with others
The clothings &bed sheets used these days are to be boiled &then washedto avoid spread of disease.
This t/t regeim should be strictly followed to get rid of scabies.
The clothings used during this period including bed sheets are to be boiled & washed thereafter.