Name the several varieties met with.
Three varieties are presented, named according to the parts involved, pediculosis capitis, pediculosis corporis, and pediculosis pubis; the parasite in each being a distinct species of pediculus.
Pediculosis Capitis.
Describe the symptoms of pediculosis capitis.
Pediculosis capitis (pediculosis capillitii), due to the presence of the pediculus capitis, occurs much more frequently in children than in adults. It is characterized by marked itching, and the formation of various inflammatory lesions, such as papules, pustules and excoriations— resulting from the irritation produced by the parasites and from the scratching to which the intense pruritus gives rise. In fact, an eczematous eruption of the pustular type soon results, attended with more or less crust formation. In consequence of the cutaneous irritation the neighboring lymphatic glands may become inflamed and swollen, and in rare cases suppurate. The occipital region is the part which is usually most profusely infested, more especially in young girls and women. In those of delicate skin, especially in children, scattered papules, vesico-papules, pustules, and excoriations may often be seen upon the forehead and neck. In some instances, however, especially in boys, there may be many pediculi present, with but little cutaneous disturbance, the itching being the sole symptom.
Fig. 79.
Pediculus Capitis x 25. (After Duhring.)
Female. Dorsal surface.
Fig. 80.