Chapter 054. Skin Manifestations of Internal Disease (Part 27)

Also associated with systemic diseases.bReviewed in section on Purpura.cReviewed in section on Papulonodular Skin Lesions.dFavors plantar surface of the foot.Note: TEN, toxic epidermal necrolysis.Livedoid vasculopathy (livedoid vasculitis; atrophie blanche) represents a combination of a vasculopathy plus intravascular thrombosis. Purpuric lesions and livedo reticularis are found in association with painful ulcerations of the lowerextremities. These ulcers are often slow to heal, but when they do, irregularly shaped white scars are formed. The majority of cases are secondary to venous hypertension, but possible underlying illnesses include cryofibrinogenemia and disorders of hypercoagulability, e.g., the antiphospholipid syndrome (Chaps. 111 and 313). ...
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Chapter 054. Skin Manifestations of Internal Disease (Part 27) Chapter 054. Skin Manifestations of Internal Disease (Part 27) a Also associated with systemic diseases. b Reviewed in section on Purpura. cReviewed in section on Papulonodular Skin Lesions. d Favors plantar surface of the foot. Note: TEN, toxic epidermal necrolysis. Livedoid vasculopathy (livedoid vasculitis; atrophie blanche) represents acombination of a vasculopathy plus intravascular thrombosis. Purpuric lesions andlivedo reticularis are found in association with painful ulcerations of the lowerextremities. These ulcers are often slow to heal, but when they do, irregularlyshaped white scars are formed. The majority of cases are secondary to venoushypertension, but possible underlying illnesses include cryofibrinogenemia anddisorders of hypercoagulability, e.g., the antiphospholipid syndrome (Chaps. 111and 313). In pyoderma gangrenosum, the border of the ulcers has a characteristicappearance of an undermined necrotic violaceous edge and a peripheralerythematous halo. The ulcers often begin as pustules that then expand ratherrapidly to a size as large as 20 cm. Although these lesions are most commonlyfound on the lower extremities, they can arise anywhere on the surface of thebody, including sites of trauma (pathergy). An estimated 30–50% of cases areidiopathic, and the most common associated disorders are ulcerative colitis andCrohns disease. Less commonly, pyoderma gangrenosum is associated withseropositive rheumatoid arthritis, acute and chronic myelogenous leukemia, hairycell leukemia, and myelofibrosis. Additional findings in these patients, even thosewith idiopathic disease, are cutaneous anergy and a monoclonal gammopathy,usually IgA. Because the histology of pyoderma gangrenosum may be nonspecific(dermal infiltrate of neutrophils when in untreated state), the diagnosis is usuallymade clinically and includes excluding less common causes of similar-appearingulcers such as necrotizing vasculitis, Meleneys ulcer (synergistic infection at a siteof trauma or surgery), dimorphic fungi, cutaneous amebiasis, spider bites, andfactitial. In the myeloproliferative disorders, the ulcers may be more superficialwith a pustulobullous border, and these lesions provide a connection betweenclassic pyoderma gangrenosum and acute febrile neutrophilic dermatosis (Sweetssyndrome). Fever and Rash The major considerations in a patient with a fever and a rash areinflammatory diseases versus infectious diseases. In the hospital setting, the mostcommon scenario is a patient who has a drug rash plus a fever secondary to anunderlying infection. However, it should be emphasized that a drug reaction canlead to both a cutaneous eruption and a fever (drug fever), especially in thesetting of DRESS. Additional inflammatory diseases that are often associated witha fever include pustular psoriasis, erythroderma, and Sweets syndrome. Lymedisease, secondary syphilis, and viral and bacterial exanthems (see Exanthems,above) are examples of infectious diseases that produce a rash and a fever. Lastly,it is important to determine whether or not the cutaneous lesions represent septicemboli (see Purpura, above). Such lesions usually have evidence of ischemia inthe form of purpura, necrosis, or impending necrosis (gunmetal-gray color). In thepatient with thrombocytopenia, however, purpura can be seen in inflammatoryreactions such as morbilliform drug eruptions and infectious lesions. Further Readings Bolognia JL et al: Dermatology, 2d ed. Philadelphia, Mosby, 2007 Braverman IM: Skin Signs of Systemic Disease, 3d ed. Philadelphia,Saunders, 1998 Callen JP et al: Dermatological Signs of Internal Disease, 3d ed.Philadelphia, Saunders, 2003 McKee PH et al: Pathology of the Skin, 3d ed. London, Elsevier, 2005 Spitz JL: Genodermatoses: A Clinical Guide to Genetic Skin Disorders, 2ded. Lippincott Williams & Wilkins, 2004