Carrots are rich in carotenes, which are substances related to vitamin A. They're found in the orange pigments and are good for you, but, if you eat lots and lots of carrots, you can develop a yellowish or orange cast to your skin. It's mostly noticeable on the soles of your feet and the palms of your hands.
Benadryl is another decongestant safe for use in cats, although it is usually not as effective as chlortrimeton in treating congestion. Benadryl is generally more beneficial with treating snake bites, reactions to vaccinations, itching, and insect bites.
OTC decongestants help relieve a stopped-up (stuffy) nose caused by a cold virus or by the flu (influenza), sinusitis, or allergies. The only OTC decongestants available in pill form are phenylephrine (1 brand name: Sudafed PE) and pseudoephedrine (1 brand name: Sudafed 12 Hour).