[What is neutrophilic urticaria?] / Qu'est-ce que l'urticaire neutrophilique ?

Some debate continues to surround the existence of neutrophilic urticaria (NU) as a nosological entity. Certain authors consider NU as a banal form of urticaria since an infiltrate predominantly made up of polynuclear neutrophils (PNN) is seen in certain cases of chronic and acute urticaria. Moreover, it has been stated that the histological appearance of chronic urticaria varies according to the time between appearance of the plaque and the performance of biopsy: the presence of PNN may occur later. According to the literature, there appear to be no specific clinical characteristics associated with the presence of PNN at histology. Most cases exhibit moderate laboratory inflammatory syndrome. Data concerning therapeutic response are contradictory: some studies have shown no significant difference in terms of therapeutic response in relation to banal urticaria, while only one study has demonstrated superior response to dapsone in the case of histologically demonstrated neutrophilic infiltrate. There does not appear to be any disease more frequently associated in the event of NU. In conclusion, the available data concerning NU are insufficient to confirm the existence of this condition. A prospective study comparing routine acute and chronic urticaria biopsies would be extremely useful to better characterise the relationships between cellular infiltrate and therapeutic response.

[Omalizumab for the treatment of chronic urticaria: Real-life findings]. / Traitement de l'urticaire chronique par omalizumab : données en vie réelle.

OBJECTIVE: Assessment of the efficacy and safety of omalizumab in chronic urticaria refractory to conventional treatment (H1-antihistamines at high dosage and montelukast) in real-life practice. PATIENTS AND METHODS: A retrospective, descriptive, single-centre study was performed of the data for all patients presenting refractory chronic spontaneous urticaria or inducible urticaria and receiving omalizumab (300mg every four weeks) from November 2012 to June 2016. RESULTS: In all, 23 patients were included. Omalizumab led to complete or significant remission in 19 patients (83%) with chronic urticaria, with remission in 9 patients (47%) occurring within 72hours of the first injection. One patient had a partial response and 3 (13%) showed no response. Only 2 patients (9%) in complete remission stopped their treatment at 1 and 3 years. 52% of patients presented non-serious adverse events, which in one case resulted in treatment withdrawal. CONCLUSION: Omalizumab exhibited good real-life efficacy in a small series of chronic urticaria patients in France.

[Hypersensitivity reactions to beta-lactam antibiotics]. / Allergies aux bêtalactamines.

Allergy to beta-lactam antibiotics is a common condition and about 10% of patients report being allergic to penicillin. However, this diagnosis is largely overestimated. Two types of allergy should be distinguished and include immediate hypersensitivity that can lead to anaphylactic shock and delayed hypersensitivity, ranging from the most common maculopapular exanthema to severe bullous toxidermia or life-threatening DRESS. Allergy challenge with oriented skin tests according to the clinical features, supplemented with oral challenge in the absence of contraindication, will confirm or invalidate the diagnosis of beta-lactam allergy and will help to identify if necessary safe alternatives to beta-lactams.

[Recurrence of drug eruption after renewed injection of iodinated contrast medium in patients with known allergic contraindications]. / Récidives de toxidermies après nouvelle injection de produit de contraste iodé chez des patients allergiques connus.

BACKGROUND: Iodinated contrast media (ICM) are used extensively by both radiologists and cardiologists. Injection of such products can induce immediate hypersensitivity reactions, some of which are IgE-mediated, and delayed hypersensitivity reaction with all types of drug eruptions being reported. Allergy tests, whether patch-tests or intradermal tests, are useful to confirm whether patients are allergic. At the end of these tests, depending on the reaction (chronology and clinical symptoms) and the results of the skin tests, patients are given an allergy card as well as a detailed certificate indicating the various ICM contraindicated and those allowed. OBSERVATIONS: We report herein three cases of patients experiencing a confirmed allergic eruption after injection of ICM, and whose recommendations and contraindication were not taken into consideration, leading to recurrence of eruption after renewed ICM injection. DISCUSSION: The three cases we report herein underscore the lack of knowledge concerning eruptions induced by ICM, particularly among radiologists. Better dissemination of information about the existence of such reactions appears necessary amongst the medical professionals concerned.

Chronic urticaria and hormones: Is there a link?

BACKGROUND: While the role of oestrogens in bradykinin angioedema (AE) has been clearly demonstrated, scarce data are available about the role of sex hormones in chronic urticaria (CU). OBJECTIVES: To gather information from a population of women with various forms of CU [chronic spontaneous urticaria (CSU), including a subtype of isolated histaminic AE and a classic subtype of association of wheals and AE, and exclusive inducible urticaria (IU)] about the impact of sex hormones and reproductive factors on their symptoms. METHODS: This was a cross-sectional study comprising interviews of 200 women consulting for CU at nine centres throughout France between May and July 2013. The dermatologists filled in an online questionnaire on the impact of reproductive factors (puberty, contraception and pregnancy) and hormonal treatments on the course of CU, including CSU and IU, in the presence of the women. RESULTS: Most of the women did not experience CU before puberty and if so, puberty did not influence the course of CU. Only 16 women had experienced a pregnancy during CU which caused a worsening of symptoms in four. Hormonal contraception was associated with aggravation in a minority of women, mostly women with CSU (10%). Women with isolated histaminic AE did not exhibit any female sex hormone dependency. CONCLUSIONS: It would appear that sex hormones act as a trigger in only a small subset of women with CU. Nevertheless, this should be taken into account to improve patient management.

Immediate hypersensitivity to iodinated contrast media: diagnostic accuracy of skin tests and intravenous provocation test with low dose.

BACKGROUND: The diagnosis of HSR to iodinated contrast media (ICM) is challenging based on clinical history and skin tests. OBJECTIVE: This study evaluates the negative predictive value (NPV) of skin tests and intravenous provocation test (IPT) with low-dose ICM in patients with suspected immediate hypersensitivity reaction (HSR) to ICM. METHODS: Thirty-seven patients with suspected immediate hypersensitivity reaction to ICM were included retrospectively. Skin tests and a single-blind placebo-controlled intravenous provocation test (IPT) with low-dose iodinated contrast media (ICM) were performed. RESULTS: Skin tests with ICM were positive in five cases (one skin prick test and five intradermal test). Thirty-six patients were challenged successfully by IPT, and only one patient had a positive challenge result, with a grade I reaction by the Ring and Messmer classification. Ten of 23 patients followed up by telephone were re-exposed to a negative tested ICM during radiologic examination; two experienced a grade I immediate reaction. CONCLUSIONS & CLINICAL RELEVANCE: For immediate hypersensitivity reaction to ICM, the NPV for skin tests and IPT with low dose was 80% (95% CI 44-97%).

[A study of 19 cases of allergy to heparins with positive skin testing]. / Étude de 19 cas d'allergie aux héparines prouvée par des tests cutanés.

BACKGROUND: Allergic hypersensitivity to unfractioned or low-molecular-weight heparins is uncommon but is known, and in particular the most common form is localized dermatitis, although such cases have seldom turned into maculopapular exanthema. Since cross-reactions with other heparins are frequent, identification of therapeutic alternatives is essential. PATIENTS AND METHODS: This retrospective study included patients referred to the Department of Dermatology and Allergology at Tenon Hospital between 2000 and 2012 with suspicion of allergy to unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH) and sensitized to at least one heparin (i.e. positive skin tests to at least one heparin). The heparins and hirudins used were tested in the forearm by means of intradermal skin tests. All patients were contacted in 2012 to establish whether they had used some form of heparin since the cutaneous allergy tests. RESULTS: Nineteen patients had at least one positive skin test for heparin; 1 patient had presented anaphylactic shock, while 18 others had presented localized eczema (12) or generalized dermatitis (6). The heparin most often responsible for these adverse reactions was enoxaparin (13/19). An LMWH was responsible in most cases (18 vs. 1 with UFH). Of these 18 patients, 16 also presented positive skin tests for UFH, 9 for synthetic heparinoid and 1 for hirudin. 11/19 patients were tested for fondaparinux (a synthetic pentasaccharid) and all had negative skin tests. 5/7 patients with negative skin tests had taken fondaparinux without any visible reaction, whereas 2 who also tested negative experienced localized eruption at the injection site. DISCUSSION: Our results underline the greater frequency of delayed hypersensitivity reactions compared with immediate reactions to heparins. Skin tests can help to identify substitution molecules. Fondaparinux might be an alternative but certain diagnosis relies on rechallenge.

Cutaneous adverse drug reaction to oral acetazolamide and skin tests.

BACKGROUND: Few cases of cutaneous adverse drug reactions (CADR) to oral acetazolamide, a non-antimicrobial sulfonamide, have been previously reported, and the interest of acetazolamide skin tests has never been studied. OBJECTIVES: We report a series of ten patients with oral acetazolamide CADR and skin tests. PATIENTS AND METHODS: The files of ten patients with CADR secondary to oral acetazolamide prescribed for cataract surgery in most cases referred between 2001 and 2011 in four French dermatology and allergy departments were retrospectively reviewed. Skin tests with acetazolamide were performed in nine patients and twelve controls. Other sulfonamides were tested in five of ten patients. RESULTS: Seven patients developed maculopapular exanthema and four had acute generalized exanthematous pustulosis. Patch tests were positive for 8/9 patients, prick tests for 2/4 and intradermal tests for 3/3. Patch and prick or intradermal test results were concordant in 2/3 positive subjects. Patch tests for other sulfonamides were negative, as were patch tests in controls. CONCLUSIONS: We report the largest series of CADR to oral acetazolamide (maculopapular exanthema or acute generalized exanthematous pustulosis). A drug eruption after cataract surgery should be investigated for accountability of acetazolamide. In view of this retrospective study, skin tests and particularly intradermal tests appear to be an important contribution to demonstrate accountability.

Five cases of contact dermatitis to a trendy pet.

Skin contact with animal hair may induce contact urticaria (syndrome) or protein contact dermatitis. We report here 5 cases of dermatitis due to contact with ferrets kept as pets. The nature of the skin lesions, i.e. eczematous dermatitis, as well as the history of our 5 cases point to protein contact dermatitis. Further studies are requested to confirm this hypothesis and to identify the mechanisms and allergens. Physicians must be aware of the possibility of contact dermatitis with ferrets, especially when the patient has no previous history of atopic dermatitis and presents dermatitis of the neck, arm and around mouth.

Evaluation of re-challenge in patients with suspected lidocaine allergy.

BACKGROUND: Lidocaine is an anaesthetic agent used worldwide in various clinical specialties. Although lidocaine hypersensitivity is very rare, clinicians frequently encounter patients with such an alleged diagnosis. Using a questionnaire, we evaluated the results of re-challenge with lidocaine, the gold standard for assessing hypersensitivity reactions in patients who claim to be allergic to this drug. METHODS: A detailed questionnaire was sent to members of the French Dermatological Society, targeting the management of patients claiming lidocaine intolerance. After analysis and recall of doubtful episodes, 199 re-challenges were made. True lidocaine hypersensitivity was finally demonstrated in only 1 patient. CONCLUSIONS: The results of this study demonstrate that patients claiming to be allergic to lidocaine are usually not, their symptoms corresponding in most cases to a vasovagal episode. Re-challenge is safe and may constitute an easy and cheap alternative to skin testing. This should be performed in specialized centres except in case of a vasovagal episode.

[Allergy in chronic urticaria]. / Bilan allergologique et urticaire chronique.

Chronic urticaria is an intricate pathology, caused by numerous factors. The number of tests depend on the practitioner but very often no aetiology is found. Allergologist play a role in this research of an aetiology that can be cured. The rate of an allergic aetiology in chronic urticaria is not known but remains weak. Allergy to the aeroallergens has not shown any responsibility in chronic urticaria. Total IgE count is not a major tool in the allergologic investigation. If needed, skin tests confirmed by specific IgE, remains the best way to confirm an allergy. The result will always be interpreted in relation with the clinical history. In addition a double blind versus placebo provocation could be realised. Diets did not show their efficiency. The role of additives are much debated as well. However if they have an influence, this is only through a non-allergic mechanism. Concerning autologous serum skin test, it should allow to identify among chronic idiopathic urticaria, those for which the aetiology could be auto immune. For half of the positive results, an histaminoliberation could be found highlighting the presence of functional autoantibodies anti FcepsilonRIalpha, anti IgE less frequently or both. Progresses are expected before proving their pathogenic role and to define when this test must be done.

[Ectopic breast cancer of the axilla]. / Carcinome mammaire ectopique primitif axillaire.

INTRODUCTION: Breast cancer is the most frequent cancer occurring in women. These cancers may rarely develop within ectopic breast tissue. We report a case of ectopic axillary lobular carcinoma presenting as an isolated skin lesion with prolonged evolution. CASE-REPORT: A 62 year-old women had a cutaneous lesion located in her left axilla for the past 4 years. The skin biopsy showed an infiltrating lobular carcinoma. A mammogram and an MRI were as unremarkable as two past mammograms performed since the beginning of the skin lesion. Surgical resection with lymph node dissection, associated with radiotherapy and hormonotherapy with tamoxifen, led to complete remission. DISCUSSION: Ectopic breast tissue is subject to physiological and pathologic changes such as benign or malignant tumours. Cancer occurring in ectopic breast tissue remains rare but this diagnosis must be suspected when confronted with a skin lesion or mass located near the normal breasts.