Allergic contact dermatitis
This is when some ingredient you're putting on your body is triggering an allergic skin reaction, Dr. Shainhouse says—and the culprit might even be coming from a natural or organic product. "You don't usually develop a rash after the first exposure," she says, "but repeated exposure sensitizes the skin in some people." Before you throw out every body product in your bathroom, start with Dr. Shainhouse's list of likely offenders: "These rashes are more likely to be caused by leave-on products–like salves, lotions, or sprays—rather than quick wash-off products like soap or shampoo."
Chances are, if you have these swollen veins in your rectal area, you already know it. But in case they're new to you, "hemorrhoids can cause bleeding, itching, and difficulty cleaning after bowel movement," says Dr. Roshini Rajapaksa, a gastroenterologist and clinical associate professor at NYU Langone Health. Dr. Rajapaksa advises taking a two-step approach to reducing the itch: first, manage the hemorrhoids themselves by reducing constipation. "Get more fiber, in your diet or [via] supplements," she says. "And drinking enough water is very important, too." For more rapid relief, look to OTC products like Preparation H Ointment, which relieves itching and discomfort and helps shrink swollen tissue. You can also try a product like Preparation H medicated wipes, which soothe with witch hazel and aloe.
Constipation can do more than produce hemorrhoids; it can also create anal fissures. (More fiber, please!) These tiny, paper cut-like tears in the skin around the anus and anal sphincter are fairly common, Dr. Shainhouse says. Two clues you might have anal fissures: stinging pain when you poop and fine streaks of bright red blood on your toilet paper. "The best treatment is to calm the area by taking sitz baths and using soothing petroleum jelly, and let them heal," Dr. Shainhouse recommends. (Moms, you may already be familiar with sitz baths from after you gave birth.)
This autoimmune inflammatory condition shows up in the form of thick pink-white, scaly plaques on your skin. "While psoriasis favors the elbows, knees and scalp, a secret hiding place is the buttock cleft and anal area," Dr. Shainhouse says. "It could be painful, but more frequently it's itchy." If you have a rash that just won't quit and/or you know psoriasis runs in your family, see your dermatologist.