(Phthiriasis pubis; Carb-lice; “Crab”)
This variety of pediculus is usually found on the hairy surfaces of the pubic region but may be transported to the hairy portions of the axilla, beard, eyebrows, eyelids or lashes. The habits of this species are like the pediculus capitis; it is, however, less active, smaller in size, and may usually be found with its head buried in the hair-follicle or near the hair root. This digging excites intense itching which causes excoriations, papules, pustules and other inflammatory lesions. The so-called maculae ceruleae consist of bluish or brownish, round or irregular, finger-sized pigmented spots and are more distinct in light-skinned people. These spots are supposed to be due to infection by the saliva of the pediculus and disappear after the destruction of the parasite. The nits are similar to those of pediculus capitis and are found glued to the hairs in the same way.
Etiology and Pathology. This form is almost exclusively observed in adults and is usually contracted during sexual intercourse. It closets, etc. It is as common in private practice as in hospital and public work. The pediculus pubis is less prolific than the head-louse but the ova hatch out and mature in about the same time.
Diagnosis. Persistent or pronounced itching of the genitalia and the presence of the pediculi and ova will reveal the nature of the disease.
Treatment. Lotions are to be preferred to ointment as a rule and there are two important “don’ts” to be observed. The hair need not be but or shaved off, as it exposes the parts to friction, and blue (mercurial) ointment should not be applied, because the resultant dermatitis is often worse than the disease. Infusion of tobacco, tincture of cocculus indicus, or mercuric chlorid, 1 to 2 grains to an ounce of cologne are serviceable. Betanaphthol, 1 dram to an ounce of lard, or ammoniated mercury in the same strength, may be preferred. A weak citrine ointment may be employed when the eyelids are affected. Solutions of vinegar, dilute acetic acid or borax will remove the nits.
Such remedies as Psorinum, Staphisagria and Sulphur may be indicated to improve the general condition of any case of persistent or neglected pediculosis.