Skin tests hypersensitivity

Brockow K, Romano A, Aberer W et al Skin testing in patients with hypersensitivity reactions to iodinated contrast media - a European multicenter study. Allergy 2009 64 234-241. 

For penicillin-allergic (nonanaphylactoid type) patients cefazolin 6 g/24 hours IV in 3 equally divided doses 6 IB Consider skin testing for oxacillin-susceptible staphylococci and questionable history of immediate-type hypersensitivity to penicillin cephalosporins should be avoided in patients with anaphylactoid-type hypersensitivity to P-lactams vancomycin should be used in these cases ... 

In a patient with a positive penicillin skin test or a history of immediate hypersensitivity to penicillin, vancomycin is the agent of choice. Vancomycin, however, kills S. aureus slowly and is generally regarded as inferior to penicillinase-resistant penicillins for MSSA. Penicillin-allergic patients who fail on vancomycin therapy should be considered for penicillin desensitization. 

Tuberculin skin testing is an important part of the care of all HIV-1-infected patients or persons at risk for HIV-1 infection. Tuberculin skin testing should be done using the Mantoux method. A tuberculin reaction of >5 mm of induration is classified as positive in persons known to have or suspected of having HIV-1 infection. Unfortunately, as the CD4 lymphocyte count declines with progression of HIV-1 disease, many patients no longer react to delayed-type hypersensitivity testing. More than 60% of persons with CD4 lymphocyte counts of <200 cells/pl may have skin test reactions of <5 mm. Thus, it is impossible to detect the presence of tuberculous infection in many HIV-l-infected individuals. 

Observations regarding the cellular immune response in PTSD are also consistent with enhanced GR responsiveness in the periphery. In one study, beclomethasone-induced vasoconstriction was increased in women PTSD subjects compared to healthy, non-trauma-exposed comparison subjects (Coupland et al. 2003). Similarly, an enhanced delayed-type hypersensitivity of skin test responses was observed in women who survived childhood sexual abuse vs those who did not (Altemus et al. 2003). Because immune responses, like endocrine ones, can be multiply regulated, these studies provide only indirect evidence of GR responsiveness. However, when considered in the context of the observation that PTSD patients showed increased expression of the re-... 

The incidence of nonallergic ampicillin eruptions is 40 to 100% in patients with concomitant Epstein-Barr virus (mononucleosis), cytomegalovirus, acute lymphocytic leukemia, lymphoma, or reticulosarcoma. Nonallergic penicillin-associated rashes are characteristically morbilliform (symmetrical, erythematous, confluent, maculopapular) eruptions on the extremities. The onset of typical nonallergic eruptions is more than 72 hours after (3-lactam exposure. The mechanism for the nonurticarial ampicillin rash is not known and is not related to IgE or type I hypersensitivity. Penicillin skin tests are not useful in the evaluation of nonurticarial ampicillin rashes. Patients with a history of nonurticarial ampicillin rashes may receive other (3-lactam antibiotics without greater risk of subsequent serious allergic reactions. 

A 75-year-old man developed triamcinolone-induced anaphylaxis and dose-related positive prick skin tests to triamcinolone, suggesting that an IgE-mediated hypersensitivity mechanism may have played a part... 

The authors of the last report commented that generalized delayed type hypersensitivity to systemic administration of a glucocorticoid is rare. Despite the potent immunosuppressive effect of glucocorticoids on immunocompetent cells, the clinical features, the skin biopsy specimen, and the positive delayed skin test reactions strongly suggested an immunological mechanism T cells were clearly involved and the high concentrations of interleukins 5, 6, and 10 were consistent with a T helper type 2 reaction. The raised concentrations of interleukin-5 were probably responsible for the blood and tissue eosinophilia. 

Levamisole was first synthesized for the treatment of parasitic infections. Later studies suggested that it increases the magnitude of delayed hypersensitivity or T cell-mediated immunity in humans. In immunodeficiency associated with Hodgkin s disease, levamisole has been noted to increase the number of T cells in vitro and to enhance skin test reactivity. Levamisole has also been widely tested in rheumatoid arthritis and found to have some efficacy. However, it has induced severe agranulocytosis (mainly in HLA-B27-positive patients), which required discontinuation of its use. The drug may also potentiate the action of fluorouracil (5-FU) in adjuvant therapy of colorectal cancer, and this combination has been approved for clinical use in the treatment of Dukes class C colorectal cancer after surgery. Its use in these cases reduces recurrences, and the mechanism... 

Malinowska, E., Kaczmarski, M., and Wasilewska, J. 2002. Total IgE levels and skin test results in children under three years of age with food hypersensitivity. Med Sci Monit 8 280-287. 

The major adverse reactions to the penicillins are hypersensitivity responses. Manifestations of hypersensitivity inclnde nrticaria, angioedema, and anaphylaxis (type 1 reaction) hemolytic anemia (type 11 reaction) interstitial nephritis, vascnlitis, and serum sickness (type 111 reaction) and contact dermatitis or Stevens-Johnson syndrome (type IV reaction). A maculopapular rash occnrs late in the treatment course of 2% to 3% of patients receiving a penicillin drug. Once a patient has had a hypersensitivity response to a penicillin, it is probable, bnt not certain, that a reaction will occur with exposure to the same penicillin or to any other penicillin. Intradermal skin tests can predict whether a patient is at risk for developing a hypersensitivity reaction to the penicillins. If the resnlts are positive, penicillins should generally be avoided. 

Green GR, Rosenblum AH, Sweet LC. Evaluation of penicillin hypersensitivity value of clinical history and skin testing with penicilloyl-polylysine and penicillin G. A cooperative prospective study of the penicillin study group of the American Academy of Allergy. J Allergy Clin Immunol 1977 60(6) 339-45. 

Clavulanic acid has a very low immunogenic and allergenic potential in animals. The possible impact of its co-administration with other beta-lactam antibiotics is unknown (53). Two patients with IgE-mediated hypersensitivity to oral co-amoxiclav and positive skin tests for clavulanic acid, but not for penicillins, both tolerated oral amoxicillin. One patient was also challenged with clavulanic acid and developed urticaria, conjunctivitis, and bronchial obstruction (54). Since co-amoxiclav has been widely used since its introduction in 1981, the frequency of hypersensitivity reactions is low. The clinical data available on sulbactam and tazobactam are stiU hm-ited and do not allow an assessment of the frequency and pattern of associated hypersensitivity reactions (55). 

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