Keratosis pilaris can indeed occur on the thighs and buttocks, as well as the arms. Folliculitis is also common on the buttocks and thighs. Folliculitis can present more acutely and progress as you describe when you had it on your bikini line, but it can also be more chronic and appear almost like acne. Keratosis pilaris usually improves by moisturizing with a lactic
acid-containing lotion. Chronic folliculitis can improve with antibacterial washes. Your dermatologist would be able to determine which treatment is best based on your examination.
