Signs and Symptoms
Although the entire body may itch, the most common locations for the lesions of scabies include:
- The areas between the fingers (finger webs)
- Inner wrists, inner elbows, and armpits
- Breasts of females and genitalia of males
- Navel (umbilicus)
- Lower abdomen
- Buttocks
- Backs of knees
Although in adults it is rare to see lesions on the face, scalp, and neck, these areas are commonly affected in children aged younger than 2 years.
The most obvious signs of scabies are pink-to-red bumps, which can look like pimples or bug bites, sometimes with scale or a scab on them. However, the tell-tale lesion of scabies is the burrow, which is small and often difficult to see. Typically, a burrow appears as a small, thread-like, scaly line (3–10 mm long), sometimes with a tiny black speck (the burrowing mite) at one end. The adult mite is about 0.3 mm long and is very difficult to see. Scabies mites crawl; they do not jump or fly.
People who are exposed to scabies may not develop itchy lesions for up to 6 weeks after becoming infested, as the immune system takes some time to develop an allergic response to the mites. However, individuals who have had scabies before may develop the rash within several days of re-exposure.
Scabies is intensely itchy, especially at night. Excessive scratching of the itchy lesions can create breaks in the skin, which may then become infected with bacteria.
A severe form of scabies, called Norwegian scabies or crusted scabies, is seen in:
- Elderly people
- Individuals with weakened immune systems (such as organ transplant recipients or people with HIV/AIDS)
- Malnourished people
- People who are physically and/or mentally impaired or disabled
In people with Norwegian/crusted scabies, the skin becomes very red and is covered with thick, white scales and crusts. The lesions are widespread, appearing over the scalp, face, elbows, knees, palms, and soles of the feet. Interestingly, these infestations may not be itchy, although the lesions may contain up to two million mites.
Who's At Risk
