Tiny threadlike burrows may appear on the skin. They range from 2-15 mm in length and have a gray, brown or red appearance. These burrows are caused by female scabies mites tunneling into the epidermal layer of skin to lay their eggs. Found most often in the areas between the fingers, the burrows may also appear on the wrists, inner knees and elbows, breasts, penis, or shoulders.

Symptoms of scabies may not develop for up to two months, but the infested person is contagious during this time. Direct prolonged skin-to-skin contact is the way scabies is usually spread. Infested persons can pass it to their sexual partner, which is the reason scabies is often classified as a sexually transmitted disease. 

When the rash starts to appear, it can often be mistaken for other skin conditions, such as eczema, hives, or psoriasis, but the itch of a scabies rash intensifies over time. Over-the-counter itch remedies don't have any effect on the itching of scabies. After several weeks, the itch is so severe that the infected person is unable to sleep or to stay asleep. The constant scratching of the rash often causes the bumps and blisters to turn into open sores which can lead to infection.

Misdiagnosis happens frequently because scabies infestation in the early stages resembles small pimples or insect bites, but within a few weeks the patient's symptoms get worse. If the infestation is the first time for a person, it may take up to six weeks for symptoms to appear. If they have had scabies before, a few days may be all it takes to see symptoms.

Crusted scabies, also known as Norwegian scabies, is a more severe form. With this type of scabies, large numbers of scabies mites and their eggs form thick crusts in the skin. The rash and itching of regular scabies may not appear, but this form is much more contagious as it can be transmitted through clothing. This type will usually occur in people who are immunosuppressed or otherwise in frail health, such as the elderly or disabled. Persons with crusted scabies need to get medical attention as soon as possible after they notice the crusted area.

Scabies is a condition that occurs across the globe, to all races and all social classes. Many scabies outbreaks occur in places where close contact is inevitable, such as nursing homes, schools, prisons, and child care facilities.