Scabies is a contagious skin disease caused by a species of mite that is very small. Symptoms include itching (especially at night); rashes; sores (abrasions) on the skin from scratching and digging; thin, pencil-mark lines on the skin. Mites may be more widespread on a baby's skin, causing pimples over the trunk, or small blisters over the palms and soles. In young children, the head, neck, shoulders, palms, and soles are involved. In older children and adults, the hands, wrists, genitals, and abdomen are involved.