Brief Answer: These seem two different issues. Detailed Answer: Hello, Welcome to XXXXXXX Though polytim b is known to cause reactions, but rash or reaction is limited to face and neck region only. Since he is having rash on shoulder and trunk , it is seems a different issue. Such rashes in children are generally due to infection or skin infections. ideal would be to let his doctor have a look. I generally prescribe oral antihistaminics and local antibiotic creams in such cases. Hope this helps.Please ask if there are doubts. Regards.