Balanitis is inflammation of the head of the penis caused by trauma or poor hygiene. The area is red, swollen and tender. Treatment is with warm compresses and an oral antibiotic. Eczema is a dry, itchy, scaly rash. Eczema of the scrotum can be intensely itchy with thickening and darkening of the scrotal skin.
Treatment is with a mild skin cleanser, moisturizer and a mild topical steroid.
Contact dermatitis is an allergic reaction. One common cause is poison ivy, which you can get on your hands and spread to your genitals by touch. Your doctor can treat you with a mild topical steroid or, for a severe case, a short course of an oral steroid. Your doctor may treat you with a moisturizer and a mild topical steroid. Certain conditions, such as diabetes, can make yeast infections more likely.