A penicillin is the drug of choice for treatment of many infections, but allergic reactions to these drugs occur frequently and, rarely, can be fatal. From 5% to 20% of patients have a history of a rash or some other reaction while taking a penicillin, but maculopapular rashes with ampicillin or amoxicillin, especially in children with infectious mononucleosis, are probably not allergic.

Only a small minority of patients who say they are allergic to penicillin will have a reaction if they take a penicillin.

Patients with seasonal allergies often experience nasal itching and congestion, sneezing, rhinorrhea, and itchy, watery eyes. Oral, intranasal, and ophthalmic preparations are widely available over the counter (OTC) for relief of symptoms. Prescription products for management of allergic rhinitis and allergic conjunctivitis are reviewed separately.

Omalizumab (Xolair – Genentech), a recombinant anti-IgE monoclonal antibody FDA-approved for treatment of allergic asthma, chronic rhinosinusitis with nasal polyps, and chronic urticaria, has now also been approved for use in conjunction with food allergen avoidance to reduce IgE-mediated food allergic reactions caused by accidental exposure in patients ≥1 year old. Omalizumab is the first drug to be approved in the US to reduce allergic reactions to more than one food. Palforzia, an oral peanut allergen powder, was approved in 2020 to mitigate allergic reactions caused by...

A reader who took the online continuing medical education (CME) exam for issue 1406 (Med Lett Drugs Ther 2012; 54:101) pointed out that the first question assumed that a rash following oral administration of ampicillin would be due to allergy. Perhaps we should have mentioned in our article on penicillin allergy that late-appearing maculopapular rashes associated with oral ampicillin or amoxicillin are generally considered non-allergic and need not preclude subsequent administration of ampicillin or amoxicillin.

The 0.15% nasal spray formulation of the H₁- antihistamine azelastine hydrochloride (Astepro Allergy; Children's Astepro Allergy – Bayer) is now available over the counter (OTC) for temporary relief of nasal congestion, runny nose, sneezing, and itchy nose due to allergic rhinitis in adults and children ≥6 years old. It is the first intranasal antihistamine to be approved by the FDA for OTC use. Other drugs that are available OTC for treatment of allergic rhinitis symptoms include oral antihistamines, intranasal corticosteroids, and mast cell stabilizers.

The nasal spray formulation of the corticosteroid fluticasone furoate is now available over the counter (OTC) as Flonase Sensimist Allergy Relief (GSK) in the same strength as the prescription product (Veramyst) for treatment of seasonal or perennial allergic rhinitis. It is the fourth intranasal corticosteroid to become available OTC.

A reader has questioned why the label for the COX-2 selective NSAID celecoxib (Celebrex, and generics), which contains a sulfonamide moiety, states that it is contraindicated for use in patients with an allergy to sulfonamides, while the labels of some other sulfonamide drugs recommend either caution or no precautions at all. The concept of cross-reactivity among sulfonamide drugs, particularly between antibacterial and nonantibacterial sulfonamides, has been controversial for many years.

The nasal spray formulation of the corticosteroid fluticasone propionate is now available over the counter (OTC) as Flonase Allergy Relief (GSK) in the same strength as the prescription product (Flonase, and generics) for patients ≥4 years old with seasonal or perennial allergic rhinitis. It is the second corticosteroid nasal spray to become available OTC; triamcinolone acetonide (Nasacort Allergy 24HR) was the first. Unlike prescription Flonase, the OTC product is FDA-approved for reduction of ocular as well as nasal symptoms. Brand-name prescription Flonase has been...

Cetirizine (Zyrtec - Pfizer), a histamine H 1 -receptor antagonist, has been approved by the US Food and Drug Administration for treatment of seasonal allergic rhinitis, perennial allergic rhinitis and chronic idiopathic urticaria in adults and children more than 12 years old.