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Best would be to stop the offending drug and use other drugs or 2nd line agents. The rashes will go away, you can apply Lactocalamine lotion on those sites. She needs proper treatment from WHO/RNTCP Government treatment regime for best results. She needs to be kept away from anyone in the family who has TB or chronic cough
to prevent spread of drug resistant TB and also other infections. Let her use handkerchief while coughing. Proper handwashing technique to prevent infection as well. Give her proper diet rich in protein like pulses, cereals, eggs, chicken, lean meat. As of her drug allergy
which is probably because of one or more of the drugs, it needs to be changed or dropped from regime. Consult her Doctor in this matter for solution and usage of possible 2nd line drugs.