Absence of melanocytes. b Normal number of melanocytes. c Platelet storage defect and restrictive lung disease secondary to deposits of ceroid-like material; one form due to mutations in β subunit of adaptor protein. d Giant lysosomal granules and recurrent infections. The differential diagnosis of localized hypomelanosis includes the following primary cutaneous disorders: idiopathic guttate hypomelanosis, postinflammatory hypopigmentation, tinea (pityriasis) versicolor, vitiligo, chemical leukoderma, nevus depigmentosus (see below), and piebaldism (Table 54-9). In this group of diseases, the areas of involvement are macules or patches with a decrease or absence of pigmentation. . | Chapter 054. Skin Manifestations of Internal Disease Part 9 Absence of melanocytes. Normal number of melanocytes. cPlatelet storage defect and restrictive lung disease secondary to deposits of ceroid-like material one form due to mutations in 0 subunit of adaptor protein. Giant lysosomal granules and recurrent infections. The differential diagnosis of localized hypomelanosis includes the following primary cutaneous disorders idiopathic guttate hypomelanosis postinflammatory hypopigmentation tinea pityriasis versicolor vitiligo chemical leukoderma nevus depigmentosus see below and piebaldism Table 54-9 . In this group of diseases the areas of involvement are macules or patches with a decrease or absence of pigmentation. Patients with vitiligo also have an increased incidence of several autoimmune disorders including hypothyroidism Graves disease pernicious anemia Addison s disease uveitis alopecia areata chronic mucocutaneous candidiasis and the polyglandular autoimmune syndromes types I and II . Diseases of the thyroid gland are the most frequently associated disorders occurring in up to 30 of patients with vitiligo. Circulating autoantibodies are often found and the most common ones are antithyroglobulin antimicrosomal and antithyroid-stimulating hormone receptor antibodies. There are four systemic diseases that should be considered in a patient with skin findings suggestive of vitiligo Vogt-Koyanagi-Harada syndrome scleroderma onchocerciasis and melanoma-associated leukoderma. A history of aseptic meningitis nontraumatic uveitis tinnitus hearing loss and or dysacusis points to the diagnosis of the Vogt-Koyanagi-Harada syndrome. In these patients the face and scalp are the most common locations of pigment loss. The vitiligolike leukoderma seen in patients with scleroderma has a clinical resemblance to idiopathic vitiligo that has begun to repigment as a result of treatment that is perifollicular macules of normal pigmentation are seen within areas of .
