Skin disorders drug-induced

In addition, data obtained from infrared, thermal, and fluorescence spectroscopic studies of the outermost layer of skin, stratum corneum (SC), and its components imply enhancer-improved permeation of solutes through the SC is associated with alterations involving the hydrocarbon chains of the SC lipid components. Data obtained from electron microscopy and x-ray diffraction reveals that the disordering of the lamellar packing is also an important mechanism for increased permeation of drugs induced by penetration enhancers (for a recent review, see Ref. 206). 

The word dermatitis denotes an inflammatory erythematous rash. The disorders discussed in this chapter include contact dermatitis, seborrheic dermatitis, diaper dermatitis, and atopic dermatitis. Drug-induced skin disorders have been associated with most commonly used medications and may present as maculopapular eruptions, fixed-drug eruptions, and photosensitivity reactions. 

Assessment for potential drug-induced skin disorders begins with a comprehensive medication history, including episodes of previous drug allergies. 

Hypersensitivity or idiosyncrasy to quinidine or other cinchona derivatives manifested by thrombocytopenia, skin eruption or febrile reactions myasthenia gravis history of thrombocytopenic purpura associated with quinidine administration digitalis intoxication manifested by arrhythmias or AV conduction disorders complete heart block left bundle branch block or other severe intraventricular conduction defects exhibiting marked QRS widening or bizarre complexes complete AV block with an AV nodal or idioventricular pacemaker aberrant ectopic impulses and abnormal rhythms due to escape mechanisms history of drug-induced torsade de pointes history of long QT syndrome. 

Immune vasculitis can also be induced by drugs. The sulfonamides, penicillin, thiouracil, anticonvulsants, and iodides have all been implicated in the initiation of hypersensitivity angiitis. Erythema multiforme is a relatively mild vasculitic skin disorder that may be secondary to drug hypersensitivity. Stevens-Johnson syndrome is probably a more severe form of this hypersensitivity reaction and consists of erythema multiforme, arthritis, nephritis, central nervous system abnormalities, and myocarditis. It has frequently been associated with sulfonamide therapy. Administration of nonhuman monoclonal or polyclonal antibodies such as rattlesnake antivenin may cause serum sickness. 

Although tumor induction has mostly been documented in patients treated for cancer, long-term cyclophosphamide treatment for non-neoplastic conditions can also increase the incidence of certain neoplasms. Whether this oncogenic effect is a consequence of drug-induced chromosomal aberrations rather than immunosuppression is unclear. An increased incidence of bladder cancers, skin cancers, and myeloproliferative disorders was found in a 20-year follow-up study of 119 patients with rheumatoid arthritis, and a high dose of cyclophosphamide (mean total dose of 80 g) was the main susceptibihty factor (47). 

Systemic lupus erythematosus and rheumatoid arthritis The possible role of interferon alfa in the development of rheumatoid arthritis or systemic lupus erythematosus has been described in isolated cases (363,364), and confirmed cases of systemic lupus erythematosus have very occasionally been reported (SED-13, 1096) (SEDA-20, 330). In most of these cases, the predominance of young patients and female sex, the presence of renal or skin involvement, the findings of positive antibodies to double-stranded DNA, and the rapid onset after the start of treatment, as well as persistence of symptoms after interferon alfa withdrawal, are more in keeping with unmasking by interferon alfa of idiopathic lupus rather than with a new drug-induced illness. The reactivation or appearance of inflammatory rheumatological disorders consistent with rheumatoid arthritis or lupus-like polyarthritis were... 

Once the health care professional identifies the specific questions to ask and can provide a reasonable description of the lesion, referral or appropriate therapies can be recommended. As there are hundreds of varieties of dermatologic disorders, here we will focus on common conditions most frequently encountered by the pharmacist and other primary care professionals, with an emphasis on skin disorders that are often treated with nonprescription medications, and on drug-induced skin disorders. Infectious skin conditions are covered in detail in Chap. 108, on skin and soft tissue infections. 

The skin is the site of several common disorders that include acne vulgaris, psoriasis, eczema dermatitis, contact dermatitis, drug-induced dermatitis, and bums. Some disorders result from viral infections such as herpes simplex and herpes zoster. Some result from fungal infections such as tinea pedis (athlete s foot) and tinea capitis (ringworm). 

Serious drug-induced skin disorders have been reviewed in relation to 2370 cases of Stevens-Johnson syndrome (2.2% of 110023 suspected adverse reactions), of which 146 cases were possibly associated with over-the-counter drugs [1 ]. The outcomes were as follows 1373 recovered or improved, 85 did not recover, 84 had sequelae, 239 died, and the outcome was unknown in 589. The authors warned that although Stevens-Johnson syndrome is rare, it can occur with any medication. They recommended that when a rash and accompanying hyperthermia develop after the administration of a medication, and Stevens-Johnson syndrome is suspected, the medicine should be withdrawn and the patient should be promptly referred to a dermatologist. 

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