Cutaneous reactions urticaria angioedema

Allergic skin reactions occur in 1-2% of patients who take nitrofurantoin and comprise about 21% of all adverse reactions to nitrofurantoin (5,71). They often occur with other reactions, such as drug fever, lung, or hver reactions. The lesions can present as pruritus, as macular, maculopapular, or vesicular rashes, urticaria, angioedema, or erjdhema multiforme (72). The frequency of serious cutaneous reactions (erythema multiforme, Stevens-Johnson syndrome, or toxic epidermal necrolysis) after nitrofurantoin has been estimated to be 7 cases per 100 000 exposed individuals (71). 

Cutaneous adverse reactions attributed to omeprazole are uncommon they include rashes, urticaria, angioedema, acute disseminated epidermal necrolysis, lichen spinulo-sus, and contact dermatitis. 

The occurrence of anaphylactic shock (Lochmann et al. 1977), acute urticaria, and angioedema (Walker 1969) have been reported and postulated to be hypersensitivity reactions. In addition, other cutaneous reactions such as rashes (Geddes et al. 1970 Maulide and Villar 1974), and the Stevens-Johnson syndrome (Fulghum and Catalano 1973 Maulide and Villar 1974) have been described, but their etiology has not been defined. However, allergic contact dermatitis due to clindamycin therapy has been observed in two patients (Coskey 1978 Herstoff 1978). 

Urticaria is the second most common cutaneous reaction induced by drugs, often in association with angioedema and anaphylaxis. Many drugs are implicated including p-lactams, NSAIDs, sulfonamides, vancomycin, and contrast media. ACE inhibitors are responsible for approximately one in six patients admitted to hospital with angioedema. 

NSAID-induced cutaneous reactions occur in a number of different clinical patterns—cross-reacting NSAID-induced urticaria and angio-edema multiple NSAID-induced urticaria and angioedema single NSAID-induced urticaria and angioedema or anaphylaxis. 

A retrospective review of 462,969 adult patients was carried out to assess the risk and pattern of cutaneous adverse reactions associated with the use of PPIs. Sixty-four patients with cutaneous adverse reactions were identified within the study population, and matched with 65 subjects, who did not experience adverse events while on therapy with PPIs. The overall prevalence of cutaneous reactions was 22.6 per 100,000 treated subjects, with specific values of 20, 16,15,10 and 3 per 100,000 for lansoprazole, pantoprazole, omeprazole, rabeprazole and esomeprazole, respectively. Most cutaneous reactions were attributed to omeprazole (n = 50 78.1%). The most frequent reaction was maculo-papular rash (43.8%), but other adverse events included cases of angioedema and/or urticaria, Stevens-Johnson syndrome and toxic epidermal necrolysis, erytiiema multiforme, eczematous drug eruption, urticarial vasculitis and fixed drug eruption. None of the patients experienced cross-reactions among individual PPIs [34 ]. 

The tolerability of rofecoxib in patients with cutaneous allergic and pseudoallergic adverse reactions to non-selective NSAIDs has been confirmed in a study in 139 patients with NSAID-induced adverse reactions 60 with urticaria alone (43%), 34 with angioedema (25%), 34 with angioedema plus urticaria (2.9%), and 2 with Stevens-Johnson syndrome (1.4%) (134). They aU underwent a single-blind, placebo-controlled oral challenge with increasing doses of rofecoxib, and 138 of them tolerated it without adverse reactions. Only one had mild urticaria on the arms. Rofecoxib may be a useful alternative in patients with NSAID hypersensitivity. 

Potassium iodide is unlikely to result in acute toxicity. Manifestations of a hypersensitivity reaction may include angioedema, cutaneous and mucosal hemorrhage, urticaria, fever, arthralgia, enlarged lymph nodes, and eosinophilia. In patients with chronic urticaria or systemic lupus erythematosus, hypocomplementemic vasculitis may be precipitated. 

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