Hello, Thanks for posting your query. The itching in armpits might be due to heat - causing sweating. The sweat contains some salts which if not removed from the skin cause itching. Sweat or perspiration often feels sticky if you sweat profusely or let the sweat dry on your skin. Drug allergy is also a likely possibility. Treatment of hyperhydrosis includes botox shots, anti perspirants and iontophoresis depending on the severity of the problem. Meanwhile you can have plenty of fluids and wash your skin often. I hope this answers your query effectively. Wishing you good health.