This spreading rash could indicate a common viral infection (like Hand, Foot, and Mouth disease), scabies, or eczema. While usually not immediately dangerous, a spreading rash with pimples requires a physical examination to rule out secondary bacterial infections. I strongly advise against using over-the-counter medicated or steroid ointments without a diagnosis, as they can worsen certain conditions. For temporary relief, keep the areas clean and dry, and apply a mild moisturizer or calamine lotion to soothe itching. Please consult a doctor or dermatologist promptly for a proper diagnosis and the correct prescription treatment.