subsequent degranulation of mast cells with release of histamine and other mediators When large amounts of these mediators are released, generalized flushing, persistent diarrhea, or hypotension may ensue Children with these symptoms require therapy directed against histamine and prostaglandin D2 Long-acting H1 blockers like cetirizine are often combined with long-acting H2 blockers like ranitidine Shorter-acting H1 blockers, such as diphenhydramine and hydroxyzine, are sometimes used as rescue agents Caution needs to be used with medications that potentially degranulate mast cells, such as opioids, NSAIDs and anesthetics, as well as avoidance of physical stimuli Children who suffer from persistent histamine-induced diarrhea may benefit from the addition of oral cromolyn sodium Over time, the condition can improve although it may not completely resolve before adolescence Hypopigmentation/Depigmentation In the neonatal period, skin findings characterized but loss of pigment are most likely related to pigment patterning in development Pigmentary mosaicism exists when an individual is composed of two or more genetically different cell populations that lead to color variation With pigmentary mosaicism, both hypoand hyperpigmentation can occur within a Blaschkoid distribution While small areas require reassurance, larger areas can be associated with neurologic, eye, cardiac, and skeletal anomalies No definitive therapy exists FIGURE 69.16 Infant with urticaria pigmentosa and positive Darier sign Partial albinism occurs when localized areas of skin and hair are devoid of pigment Ocular albinism is also seen Two syndromes with albinism are Waardenburg syndrome (white forelock, heterochromia of the iris, and sensorineural hearing loss) and Chediak–Higashi syndrome (immunodeficiency and leukocytes with giant granules) Loss of pigmentation can be a result of the absence of melanocytes as in vitiligo and halo nevi Vitiligo is a symmetric, patchy loss of pigmentation with a likely autoimmune etiology Hairs located in areas of vitiligo are often white Vitiligo can be associated with alopecia areata, pernicious anemia, Addison disease, hypothyroidism, diabetes mellitus, hypoparathyroidism, and other endocrine disorders Suppression of melanocytic pigment production can cause loss of pigmentation, as in postinflammatory hypopigmentation An example of this condition is the white patch of hypopigmentation and scaling often seen on the face, trunk, or extremities of children with atopic eczema The ash-leaf macule is a flat, hypopigmented (whitish) spot that is present in more than 90% of patients with tuberous sclerosis Hyperpigmentation In the neonatal period, hyperpigmented birth marks are relatively common Pigment deep in the dermis appears gray or blue at the surface of the skin Mongolian blue spots, now called dermal melanocytosis, are an example of this phenomenon ( Fig 69.17 ) The Nevus of Ota is dermal pigment in the distribution of the ophthalmic branch of the fifth nerve; this pigmentation can also involve the sclera and palate Patients with Nevus of Ota have a risk of glaucoma FIGURE 69.17 Dark blue patches on the buttocks and back of infant with dermal melanocytosis, formerly called Mongolian spots Additionally, certain syndromes such neurofibromatosis, are associated with early-onset pigmented skin lesions Patients with this disease can initially present with café-au-lait spots, which are flat, nonpalpable, coffee-colored lesions of varying size and shape When six or more lesions are present, greater than 0.5 cm in size, neurofibromatosis should be considered The Peutz–Jeghers syndrome is a dominantly inherited condition that includes freckle-like lesions of the lips, nose, buccal mucosa, fingertips, and subungual areas associated with polyps in the small intestine, stomach, or colon Melena and intussusception are the chief complications that may develop, usually in the second decade of life McCune–