Chapter 054. Skin Manifestations of Internal Disease (Part 11)

Also lentigines.bPolyostotic fibrous dysplasia.cSee also "Papulonodular Skin Lesions."dLate 1980s.A proliferation of melanocytes results in the following pigmented lesions: lentigo, melanocytic nevus, and melanoma (Chap. 83). In an adult, the majority of lentigines are related to sun exposure, which explains their distribution., in the Peutz-Jeghers and LEOPARD [lentigines; ECG abnormalities, primarily conduction defects; ocular hypertelorism; pulmonary stenosis andsubaortic valvular stenosis; abnormal genitalia (cryptorchidism, hypospadias); retardation of growth; and deafness (sensorineural)] syndromes, lentigines do serve as a clue to systemic disease. In LEOPARD syndrome, hundreds of lentigines develop during childhood and are scattered over the entire surface of the body. ...
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Chapter 054. Skin Manifestations of Internal Disease (Part 11) Chapter 054. Skin Manifestations of Internal Disease (Part 11) a Also lentigines. b Polyostotic fibrous dysplasia. c See also Papulonodular Skin Lesions. d Late 1980s. A proliferation of melanocytes results in the following pigmented lesions:lentigo, melanocytic nevus, and melanoma (Chap. 83). In an adult, the majority oflentigines are related to sun exposure, which explains their distribution. , in the Peutz-Jeghers and LEOPARD [lentigines; ECG abnormalities,primarily conduction defects; ocular hypertelorism; pulmonary stenosis andsubaortic valvular stenosis; abnormal genitalia (cryptorchidism, hypospadias);retardation of growth; and deafness (sensorineural)] syndromes, lentigines doserve as a clue to systemic disease. In LEOPARD syndrome, hundreds oflentigines develop during childhood and are scattered over the entire surface of thebody. The lentigines in patients with Peutz-Jeghers syndrome are locatedprimarily around the nose and mouth, on the hands and feet, and within the oralcavity. While the pigmented macules on the face may fade with age, the orallesions persist. However, similar intraoral lesions are also seen in Addisonsdisease and as a normal finding in darkly pigmented individuals. Patients with this autosomal dominant syndrome (due to mutations in anovel serine threonine kinase gene) have multiple benign polyps of thegastrointestinal tract, testicular tumors, and an increased risk of developinggastrointestinal (primarily colon), pancreatic, and gynecologic cancers. In the Carney complex, numerous lentigines are also seen, but inassociation with cardiac myxomas. This autosomal dominant disorder is alsoknown as the LAMB (lentigines, atrial myxomas, mucocutaneous myxomas, andblue nevi) syndrome or NAME [nevi, atrial myxoma, myxoid neurofibroma, andephelides (freckles)] syndrome. These patients can also have evidence ofendocrine overactivity in the form of Cushings syndrome, acromegaly, or sexualprecocity. The third type of localized hyperpigmentation is due to a local increase inpigment production, and it includes ephelides and café au lait macules (CALM).The latter are most commonly associated with two disorders—neurofibromatosis(NF) and McCune-Albright syndrome. CALM are flat, uniformly brown in color(usually two shades darker than uninvolved skin), and can vary in size from 0.5–12 cm. Approximately 80–90% of adult patients with type I NF will have six ormore CALM measuring ≥ 1.5 cm in diameter. Additional findings are discussed inthe section on neurofibromas (see Papulonodular Skin Lesions, below). In comparison with NF, the CALM in patients with McCune-Albrightsyndrome [polyostotic fibrous dysplasia with precocious puberty in females due tomosaicism for an activating mutation in a G protein (G s α) gene] are usuallylarger, more irregular in outline, and tend to respect the midline. CALM have also been associated with pulmonary stenosis (Watsonsyndrome), tuberous sclerosis, the LEOPARD syndrome, and multiple endocrineneoplasia (MEN), but a few such lesions can be found in normal individuals. In incontinentia pigmenti, dyskeratosis congenita, and bleomycinpigmentation, the areas of localized hyperpigmentation form a pattern—swirled inthe first, reticulated in the second, and flagellate in the third. In dyskeratosiscongenita, atrophic reticulated hyperpigmentation is seen on the neck, trunk, andthighs and is accompanied by nail dystrophy, pancytopenia, and leukoplakia of theoral and anal mucosae. The latter often develops into squamous cell carcinoma. In addition to theflagellate pigmentation (linear streaks) on the trunk, patients receiving bleomycinoften have hyperpigmentation overlying the elbows, knees, and small joints of thehand. Localized hyperpigmentation is seen as a side effect of several othersystemic medications, including those that produce fixed drug reactions[nonsteroidal anti-inflammatory drugs (NSAIDs), sulfonamides, barbiturates, andtetracyclines] and those that can complex with melanin (antimalarials) or iron(minocycline). Fixed drug eruptions recur in the exact same location as circularareas of erythema that can become bullous and then resolve as brown macules.The eruption usually appears within hours of administration of the offendingagent, and common locations include the genitalia, extremities, and perioralregion. Chloroquine and hydroxychloroquine produce gray-brown to blue-blackdiscoloration of the shins, hard palate, and face, while blue macules (oftenmisdiagnosed as bruises) can be seen on the lower ...