This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Skin
Non-pigmenting fixed reactions is caused by: 
Select and explain. 
A. Sulphonamides, B. Ampicillin, C. Pseudoephedrine, D. Carbamazepine
C: Pseudoephedrine
Answer: C: Pseudoephedrine 
Explanation: Non-pigmenting fixed reactions have been repoed with sympathomimetic agents pseudoephedrine, tetryzoline hydrochloride, difunisal, thiopental (thiopentone), piroxicam, Radiopaque contrast medium iothalamate, arsphenamine paracetamol. Ref: Rook's textbook of dermatology, 8th edition, Pg 75.48.