Chapter 054. Skin Manifestations of Internal Disease (Part 3) Drug-induced erythroderma (exfoliative dermatitis) may begin as an exanthematous (morbilliform) eruption (Chap. 56) or may arise as diffuse erythema. A number of drugs can produce an erythroderma, including penicillins, sulfonamides, carbamazepine, phenytoin, gold, allopurinol, and zalcitabine. Fever and peripheral eosinophilia often accompany the eruption, and there may also be facial swelling, hepatitis, and allergic interstitial nephritis; this constellation is frequently referred to as drug reaction with eosinophilia and systemic symptoms (DRESS). In addition, reactions to anticonvulsants can lead to a pseudolymphoma syndrome (with adenopathy and circulating atypical lymphocytes), while reactions to allopurinol may be accompanied by gastrointestinal bleeding. The most common malignancy that is associated with erythroderma is CTCL; in some series, up to 25% of the cases of erythroderma were due to CTCL. The patient may progress from isolated plaques and tumors, but more commonly the erythroderma is present throughout the course of the disease (Sézary syndrome). In the Sézary syndrome, there are circulating atypical T lymphocytes, pruritus, and lymphadenopathy. In cases of erythroderma where there is no apparent cause (idiopathic), longitudinal follow-up is mandatory to monitor for the possible development of CTCL. There have been isolated case reports of erythroderma secondary to some solid tumors—lung, liver, prostate, thyroid, and colon—but it is usually in a late stage of the disease. Alopecia (Table 54-4) The two major forms of alopecia are scarring and nonscarring. In scarring alopecia there are associated fibrosis, inflammation, and loss of hair follicles. A smooth scalp with a decreased number of follicular openings is usually observed clinically, but in some cases the changes are seen only in biopsy specimens from the affected areas. In nonscarring alopecia the hair shafts are gone, but the hair follicles are preserved, explaining the reversible nature of nonscarring alopecia. Table 54-4 Causes of Alopecia I. Nonscarring alopecia A. Primary cutaneous disorders 1. Telogen effluvium 2. Androgenetic alopecia 3. Alopecia areata 4. Tinea capitis 5. Traumatic alopecia a B. Drugs C. Systemic diseases 1. Lupus erythematosus 2. Secondary syphilis 3. Hypothyroidism 4. Hyperthyroidism 5. Hypopituitarism 6. Deficiencies of protein, iron, biotin, and zinc II. Scarring alopecia A. Primary cutaneous disorders 1. Cutaneous lupus (chronic discoid) 2. Lichen planus 3. Folliculitis decalvans 4. Linear scleroderma (morphea) 5. Central centrifugal cicatricial alopecia B. Systemic diseases 1. Lupus erythematosus 2. Sarcoidosis 3. Cutaneous metastases . Chapter 054. Skin Manifestations of Internal Disease (Part 3) Drug-induced erythroderma (exfoliative dermatitis) may begin. 25% of the cases of erythroderma were due to CTCL. The patient may progress from isolated plaques and tumors, but more commonly the erythroderma is present throughout the course of the disease. stage of the disease. Alopecia (Table 54-4) The two major forms of alopecia are scarring and nonscarring. In scarring alopecia there are associated fibrosis, inflammation, and loss of hair