Scabies is another condition that, in infants, can be very difficult to distinguish from atopic dermatitis, as both conditions are highly itchy and can occur in similar widespread distribution. Scabies is a common infectious dermatosis produced by infestation with the Sarcoptes scabiei mite. It results when an impregnated female mite burrows through the outer epidermis and deposits her eggs in the skin.
The rash of scabies may appear papular, nodular, eczematous, or urticarial (as hives); all of these types are often seen together in the same patient. In infantile scabies, small pustules are often seen on the lateral surfaces of the palms and soles; these areas are not typical of atopic dermatitis. Facial involvement is also more typical of atopic dermatitis than scabies.
The presence of burrows indicates scabies. If necessary for confirmation, a parasite slide preparation may be performed in attempt to visualize the mite, eggs, or fecal material. Other family members should be queried regarding recent onset of itching or rash that can lead the examiner to the diagnosis of scabies.
The treatment of choice is 5 percent permethrin cream. Adults and children over the age of 2 are treated from the neck down; infants should have the head treated, as well. Success of treatment depends on all family members being treated simultaneously. Clothing and bedding should be washed in hot water.