Ms Mira it is quite timely that you have sought professional help. Doxycyclin is a very broad spectrum antibiotic that does away with even the normal flora-the organisms that are normally present on body surfaces and organs. This in turn gives a chance to the pathogenic -the disease causing organisms to get selected and flourish in an environment of lack of competition by the normal flora. In your loving daughter s case the fungus is getting selected and is flourishing in nails. Doxycyclin should not be taken for long periods of time at least not as long as your daughter has been taking. So in a way now she is in a Antibiotic induced Immune deficient state. The solution of the problem is to stop all the antibiotics that she is taking. Another thing is to do her liver function tests-AST,ALT and Bilirubin to see that there s no damage done by antibiotics therein. For Asthma the steroids and inhalers are the mainstay of treatment. But orally it is not advisable to take potent steroids now as she is developing Fungal infections already-indicating her deficient immune status. On the same hand as she has multiple Atopies-as you are saying she has dermatitis too, she has to take at least Topical Steroids. I think Seretide inhaler or Disc 100/25 two puffs twice a day taken in the correct manner will be good for her breathing. For Dermatitis, tell her to arrange Betamethasone or Hydrocortisone oint. Antibiotics are needed in both the conditions only if she s having superimposed pathogenic organisms grown. For her fungal infection of feet, tell her to apply Nizoral[ketoconazole] ointment and pare the nails well without causing disfigurement of them and rounding the margins. Since all the above are prescription medications , she might need to go to her General Practitioner to get the prescription. Hope it helps.