The most common cause of dry skin and red bumps in the genital region is indeed just that -- irritation and chafing. It responds well to keeping the skin clean and dry, using a good moisturizing lotion, and wearing absorbent cotton underwear. In areas of frequent shaving, another possibility is in grown hairs, which happen when the hair shaft doubles back on itself. These usually respond with decreased shaving and gentle exfoliation. The major sexually transmitted infection that can cause red bumps is herpes. However, herpes causes painful, burning round blistered lesions containing clear fluid on a red base. When the lesions rupture they may form small slowly healing ulcers. However, this does not sound like the rash that you have described. As always the diagnosis and the management of your particular concerns will require a physical examination by your personal physician. Setting up an office visit with your primary care doctor
or your dermatologist
might be advised.