[The relevance of diagnostic criteria for latent tuberculosis before initiation of TNF-alpha inhibitors in psoriasis patients]. / Pertinence des critères diagnostiques de tuberculose latente avant traitement du psoriasis par anti-TNF-alpha.

BACKGROUND: Initiation of anti-TNF-alpha therapy requires prior screening for and treatment of tuberculosis. Diagnosis of relating to tuberculosis is based primarily on measurement of the papule induced by intradermal reaction to tuberculin (IDR). In this article, we discuss the validity of this criterion and the potential consequences of its use in relation to 15 patients. PATIENTS AND METHODS: This was a retrospective case study of patients presenting psoriasis and eligible for antibiotic therapy in whom latent tuberculosis was diagnosed and who received combined prophylactic antitubercular treatment for three months. All patients underwent thorough questioning and clinical examination, chest x-ray and QuantiFERON (QTF) testing, and all except one were tested for IDR. RESULTS: Thirteen patients were considered carriers of latent tuberculosis based on IDR greater than 5 mm, and on positive QTF for two others, one of whom had a documented history of primary tubercular infection. Six of these 15 patients (40%) developed hepatic cytolysis ascribable to their antitubercular treatment. DISCUSSION: Analysis of the respective characteristics of the IDR and QTF tests showed that only five of the 15 patients in our study were in fact presenting authentic latent tuberculosis, thereby suggesting that the diagnostic criteria for latent tuberculosis recommended by the French Medicines Agency (AFSSAPS), which are based solely on the size of the papule arising from IDR, are unsuitable for patients with psoriasis pending anti-TNF therapy. In our view, screening for latent tuberculosis in this patient population should involve both IDR for its sensitivity and QTF for its specificity, thereby avoiding overdiagnosis of tuberculosis leading to pointless exposure of patients to the risk of hepatic toxicity associated with antitubercular medication. CONCLUSION: We strongly recommend a change in the recommendations for prevention of tuberculosis by antibiotic therapy in patients with psoriasis, and that the review panels should include at least one dermatologist.

Detection and quantification of drug-specific T cells in penicillin allergy.

Drug allergic reactions presenting as maculo-papular exanthema (MPE) are mediated by drug-specific T cells. In this study, the frequency of circulating specific T cells was analyzed by interferon-gamma (IFN-gamma) enzyme-linked immunospot assay in 22 patients with an allergic MPE to amoxicillin (amox). Amox-specific circulating T cells were detected in 20/22 patients with frequencies ranging from 1 : 8000 to 1 : 30 000 circulating leucocytes. No reactivity was observed in 46 control patients, including 15 patients with immunoglobulin E-mediated allergy to amoxicillin, 11 patients with a history of drug-induced MPE but tolerant to amoxicillin and 20 healthy individuals. Furthermore, amox-specific T cells were still detectable several years after the occurrence of the allergic reaction even after strict drug avoidance. Finally, analysis of drug-specific T cells in one patient allergic to ticarcillin (a penicillin antibiotic distinct from amox) revealed the presence of IFN-gamma-producing T cells reactive to ticarcillin and several other betalactam antibiotics, suggesting that the IFN-gamma ELISPOT assay is able to detect T cell cross-reactivity against chemically related drugs. These findings confirm that drug-induced MPE is associated with the presence of specific T cells in blood and further suggest that the IFN-gamma ELISPOT is a sensitive assay which could improve the diagnosis of betalactam allergy.

[Tolerability of oral administration of carboxymethylcellulose in two patients presenting anaphylactic reaction after carboxymethylcellulose injection]. / Tolérance de la carboxyméthylcellulose par voie orale chez deux malades ayant développé une anaphylaxie à la carboxyméthylcellulose injectable.

BACKGROUND: Carboxymethylcellulose is a high-molecular-weight polysaccharide molecule used as a binding agent, for coating molecules and to increase the viscosity of formulations. It is present in a large number of pharmaceutical products but is also found in food and cosmetics. CASE-REPORT: We report two cases of patients who presented anaphylactic reactions immediately after localised corticosteroid injections; intra-articular for the first and intralesional for the second. Allergological testing for different corticosteroids and carboxymethylcellulose by means of prick-tests and intradermal testing indicated that the immediate hypersensitivity reaction was caused by the excipient, carboxymethylcellulose. The excellent safety of oral reintroduction of carboxymethylcellulose in a pharmaceutical preparation in these two patients confirmed that this large molecule is not absorbed through the digestive system. DISCUSSION: The avoidance list of products containing carboxymethylcellulose could be greatly reduced and limited to only injectable pharmaceutical preparations containing carboxymethylcellulose and to oral contrast media containing large quantities of carboxymethylcellulose.

[Impact of corticosteroid withdrawal in chronic urticaria: a prospective study of 17 patients]. / Effet de l'arrêt des corticoïdes au cours de l'urticaire chronique (étude prospective de 17 malades).

BACKGROUND: Although two reports have indicated benefits of oral steroids in acute urticaria, the 2003 French guidelines emphasized their inefficacy in the treatment of idiopathic chronic urticaria, and the lack of studies. We present the results of a prospective study in 17 patients presenting severe chronic urticaria who agreed to stop taking oral steroids over a one-year period. PATIENTS AND METHODS: This single-centre prospective study included adults (1) presenting chronic urticaria as defined by the French consensus conference committee on chronic urticaria (2003), (2) exhibiting at least two of the following three criteria: sleep disturbance due to itching, repeated angioedema, general symptoms; (3) unresponsive or mildly improved by antihistaminic (anti-H1) therapy; (4) receiving oral steroids at least three days per month. After inclusion in the study, oral steroids were stopped either immediately or gradually, on a case-by-case basis. Two different anti-H1 agents were prescribed at inclusion with follow-up visits two, four and 12 months after complete withdrawal of oral steroids. RESULTS: Seventeen patients were included (M/F sex-ratio: 0.54; mean age: 40 years). General signs (fever, arthralgia, various pains), delayed pressure urticaria, and idiopathic cutaneous vasculitis were noted respectively, in seven, nine and three cases. Oral steroids had been taken for three to 30 days per month before inclusion. Three patients had received prior treatment (e.g., immunosuppressants), with no improvement. After withdrawal of oral steroids, (1) 47% of patients presented a short relapse and/or worsening of chronic urticaria, (2) three patients dropped out of the study at four months (persistence of chronic urticaria unacceptable to patients, despite a clinical score showing mild response), (3) six (35%) had complete remission of chronic urticaria at 12 months, with delayed pressure urticaria in three of these cases, (4) eight (47%) had partial remission, five of whom had delayed pressure urticaria, (5) lasting remission of general symptoms. DISCUSSION: Our study shows that most cases of chronic urticaria are managed without oral steroids since inefficacy of anti-H1 drugs is generally only temporary. After withdrawal of oral steroids, a short increase in chronic urticaria was frequently observed with constant remission from extracutaneous signs and/or histological evidence of vasculitis. We suggest an active role of oral steroids in the failure of anti-H1 therapy. Moreover, oral steroids do not seem to confer any benefits in delayed pressure urticaria, and pending further prospective controlled studies, we recommend that these drugs be prescribed sparingly in chronic urticaria.

[Immediate reactions to local anesthetics: diagnostic and therapeutic procedures]. / Réactions d'allure immédiate aux anesthésiques locaux: démarche diagnostique et thérapeutique.

BACKGROUND: Despite the widespread use of local anesthetics and frequently reported adverse reactions, true IgE-mediated allergy to local anesthetics is extremely rare. We report on 80 patients seen in our department for adverse reactions to local anesthetics, and we propose a clinical strategy to confirm or rule out immediate allergy to local anesthetics. PATIENTS AND METHODS: We retrospectively analyzed the medical files of all patients referred to our department by their doctor or dentist for suspected immediate allergic reaction to local anesthetics between September 2001 and May 2004. These patients underwent skin tests (prick test and intradermal tests) exploring immediate allergy. RESULTS: Eighty cases were tested in our department during this period. The most common symptoms were facial edema or dizziness following injection of an anesthetic occurring between a few seconds and more than 48 hours after administration. The causative local anesthetics were of the amide group in 91% of cases and of the ester group in 9% of cases. Seventy-nine patients had negative skin tests, allowing us to eliminate the diagnosis of immediate allergy, and the anesthetic could be reinjected with good tolerability. One patient presented with positive skin tests to lidocaine and cross reactivity to mepivacaine. COMMENTS: Adverse reactions to local anesthetics are common and are mostly of pharmacological or toxic origin. However, allergic accidents with local anesthetics are rare and are mostly of type IV involving specific T cells. Immediate allergy to local anesthetics remains extremely rare with less than 10 authentic documented cases being published to date. Skin tests offer a reliable method for exploring immediate allergy in our experience and we propose a diagnostic strategy to confirm or rule out immediate allergy to local anesthetics.