Every time I sweat, my skin starts itching and I end up scratching. Thereby causing boils in the area. I'm a known hypothyroidism patient and have been taking eltroxin 100 mg for the past 30 yrs. I have increased my water intake. Even then my skin is slightly dry. I have irritation even in my scalp. Small heat boils appear during summer and takes long time to get cured. I have dark skin on my back, around the elbows, left thigh around the shin area in both legs.