Doctors give unbiased, trusted information on whether Furadantin can cause or treat Allergies: Dr. Lutwick on nitrofurantoin sulfa allergy: It is certainly possible. Causes. Penicillin allergy occurs when your immune system becomes hypersensitive to the drug — mistakenly reacting to the drug as a harmful substance, as if it were a viral or bacterial infection. 2013 Penicillin Allergy and Cross-reactivity with other Beta-lactams. Mohammadreza Javadi1,3, Kheirollah Gholami2, Hassan Torkamandi 3, Alireza Hayatshahi 1,3 PENICILLIN ALLERGY OVERVIEW. Overall, about 10 percent of people report some type of unwanted reaction to penicillin, and serious and even fatal allergic reactions do occur. Nitrofurantoin antibiotic is very often used to treat urinary tract infections. Allergic reactions to this is rather uncommon. However, when it happens the skin reactions could show up as itching, swelling of skin, eczema, and even serious conditions such as stevens-johnson syndrome. Other symptoms affecting gastrointestinal , urinary, blood. Cephalexin for dogs is an antibiotic medication used to fight a wide variety of bacterial infections. Cephalexin cannot be obtained without a prescription from a veterinarian, and is not an effective way to treat infections that are caused by worms, parasites, fungus or a virus. Imipenem may also cause allergic reactions in people with penicillin allergy and should be avoided. People with penicillin allergy are at higher risk of developing an allergy to sulfa antibiotics. Detailed Cephalexin dosage information for adults and children. Includes dosages for Bacterial Infection, Cystitis, Skin or Soft Tissue Infection and more; plus renal, liver and dialysis adjustments. Penicillin allergy is the most common drug allergy and is reported in up to 15 percent of hospitalized patients. A frequent clinical question is whether these p Cefalexin, also spelled cephalexin, is an antibiotic that can treat a number of bacterial infections. It kills gram-positive and some gram-negative bacteria by disrupting the growth of the bacterial cell wall. Cefalexin is a beta-lactam antibiotic within the class of first-generation cephalosporins. It works similarly to other agents within.