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to examine their skin when possible In contrast to adults, infants may develop blisters and exhibit lesions on the head and face The diagnosis is made by scraping involved skin and looking for mites under the 10× microscope objective ( Fig 88.5 ) Once an infestation occurs, it usually takes month for sensitization and pruritus to develop FIGURE 88.5 Scabies mite Louse Infestation Three forms of lice infest humans: (i) the head louse, (ii) the body louse, and (iii) the pubic or crab louse ( Fig 88.6 ) The major louse infestation in children involves the scalp and causes pruritus The female attaches her eggs to the hair shaft The egg then hatches, leaving behind numerous nits that resemble dandruff Secondary infection can occur from vigorous scratching Body lice generally reside in the seams of clothing and lay their eggs there They go to the body to feed, particularly the interscapular, shoulder, and waist areas Red pruritic puncta that become papular and wheal-like then occur Pubic lice occur in the genital area, lower abdomen, axillae, and eyelashes Transmission is usually venereal Blue macules (maculae caeruleae), caused by the bites, are to 15 mm in diameter and can be seen on the thighs, abdomen, or thorax of infested persons FIGURE 88.6 Louse Because the body louse resides in clothing, therapy consists mainly of disinfecting the clothing with steam under pressure Pediculosis capitis is usually effectively treated with 1% permethrin or pyrethrin creme rinse though resistance to this medication is not uncommon The patient’s hair should be shampooed, rinsed, and toweled dry Enough medication to saturate the hair and scalp is applied The medication is washed out after 10 minutes Additionally, benzyl alcohol–containing products (Ulesfia) and topical ivermectin (Sklice) products can also be used Patients with resistant disease may also respond to topical petrolatum applied to hair and scalp nightly for week as a lice suffocant or trimethoprim-sulfamethoxazole given orally for to days, which kills the symbiotic parasite present in the GI tract of head lice Pediculosis pubis is best treated with the same permethrin or pyrethrin preparations used for head lice Any nits are removed with a fine-toothed comb The safest treatment for lice in the eyelashes is the application of Vaseline twice daily for days The lice stick to the Vaseline, cannot feed, and die Vascular Papules and Nodules Vascular papules and nodules can be congenital or acquired Those in infants generally fall in the category of benign with hemangiomas being most common Other vascular nodules, including kaposiform hemangioendotheliomas and sarcomas, should be considered when vascular papules or nodules feel firm or not follow the natural history of infantile or congenital hemangiomas Acquired lesions include Spitz nevi and pyogenic granulomas Spitz nevus Spitz nevi appear suddenly between and 13 years of age Preferred sites of growth include the cheek, shoulder, and upper extremities ( Fig 88.7 ) The lesion has a pink to red surface because of numerous dilated blood vessels Pressure produces blanching of this pink to red color The lesions can reach 1.5 cm in diameter but are completely benign Pigmented Spitz nevi, another variant of Spitz nevi, often appear black in the skin rather than pink-red, and their appearance is often worrisome for malignant melanoma Because the histologic appearance of these lesions can be confused easily with a malignant melanoma, an experienced histopathologist should interpret the findings Most clinicians still recommend that Spitz nevi be removed surgically Pyogenic granulomas Pyogenic granulomas ( Fig 88.8 ) are bright red to reddish-brown or blue-black pedunculated, vascular papules/nodules ranging from 0.5 to cm in size that develop rapidly at the site of an injury, such as a cut, scratch, insect bite, or burn Pyogenic granulomas occur commonly in children and young adults, usually on the fingers, face, hands, and forearms They bleed easily Generally, they are asymptomatic Because spontaneous disappearance is rare, patients should be referred for definitive treatment, typically with curettage, excision, electrosurgery, cryosurgery, laser surgery, or some combination of these various modalities FIGURE 88.7 Spitz nevus Yellow, Tan, or Brown Papules Many papules are yellow, tan, or brown These include the lesions seen in urticaria pigmentosa (see Chapter 69 Rash: Neonatal ), flat warts, xanthomas, insect bites, juvenile xanthogranulomas (JXGs) as well as melanocytic nevi One way to differentiate the various papules from one another is to scratch them If hiving of a scratched lesion (Darier sign) occurs within a short period of time (3 to minutes), the lesion likely contains mast cells (i.e., a mastocytoma or urticaria pigmentosa) ( Fig 88.9 ) Make sure to scratch normal skin to rule out the presence of dermatographism The latter condition will produce a falsepositive Darier sign When no urtication occurs, a biopsy may be helpful Flat warts tend to be grouped, are flat topped, and can be autoinoculated in scratch lines (pseudo-Koebner phenomenon) Lesions characteristic for JXGs are not flat topped, tend to be singular in number (or when multiple are scattered about), and not demonstrate the Koebner phenomenon (recapitulation of the eruption in