Hi, There are various possible causes of itchy red bumps on the rib cage, including: * Contact dermatitis: This occurs when the skin comes in contact with an irritant or allergen, such as poison ivy, chemicals in soaps or detergents, or certain fabrics. * Shingles: This is a viral infection caused by the same virus that causes chickenpox. It can cause a painful, itchy rash that usually appears in a band or small area on one side of the body, such as the rib cage. * Scabies: This is a skin infestation caused by tiny mites that burrow into the skin and cause a rash that is often itchy and can occur in clusters. * Folliculitis: This is an infection of hair follicles that can cause small, itchy bumps on the skin. * Eczema: This is a chronic skin condition that can cause itchy, red, and scaly patches of skin. Without a physical examination and a more detailed history, it is difficult to determine the exact cause of your itchy red bumps. It is recommended to see a healthcare provider or a dermatologist for an accurate diagnosis and appropriate treatment. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Priyanka, General & Family Physician