Carmen D'Amelio

Successful desensitization in a child with delayed cotrimoxazole hypersensitivity: a case report

To the Editor: Sulfonamides are effective drugs for the treatment of infectious diseases caused by a number of pathogens including Grampositive bacteria, Gram-negative bacteria, and protozoa. The probability of severe allergic reactions to this group of drugs and the development of different families of antimicrobials have caused a limited usage to a few specific indications in certain groups of patients. Trimethoprim is a bacteriostatic agent which is commonly used in combination with sulfamethoxazole due to their synergic effect, known as cotrimoxazole. Several allergic reactions to cotrimoxazole, ranging from mild to potentially fatal syndromes such as Steven Johnson’s or toxic epidermal necrolysis, have been described (1). According to literature, sulfamethoxazole is the culprit of most of the allergic reactions induced by the association of trimethoprim–sulfamethoxazole (2). We present the case of a 6-year-old boy with an atopic history of grass pollen-induced rhinoconjunctivitis ongoing treatment with specific sublingual immunotherapy. He had history of transient, moderate eosinophilia (up to 1850 cells/ll) during grass pollen season in 2011 and 2012. The patient was diagnosed with right calcaneus chronic osteomyelitis in October 2010 and received different antimicrobials with recurrence of the disease. He presented for the first time in our hospital in May 2011 with a chief complaint of right heel pain. Imaging studies showed an inflammatory focus that suggested a recurrence of the disease. Treatment with ceftriaxone and vancomycin was empirically started. A fine needle aspiration cytology reported the presence of Staphylococcus warneri, methicillin sensitive. He underwent surgical cleaning a month later followed by amoxicillin–clavulanic acid treatment for four weeks. The patient was apparently well until January 2013 when he was brought back to the hospital due to heel pain associated with impairment in walking. He was diagnosed with recurrence of the infection and started treatment with cotrimoxazole and rifampicin, for 12-week duration. Eight days later, the patient presented with a papular pruritic rash in his both upper and lower extremities. Rifampicin was discontinued and was maintained with cotrimoxazole and antihistamines. The rash reappeared after four days, now observed in photoexposed areas (Fig. 1). He was then referred to Allergology Department for further evaluation and management. Skin prick tests (SPT) with sulfamethoxazole (100 mg/ml), trimethoprim (32 mg/ml), and rifampicin (60 mg/ml) and intradermal skin tests (ID) with sulfamethoxazole (10 mg/ml) and rifampicin (1 mg/ml) were performed according to the European Academy of Allergy and Clinical Immunology guidelines. Laboratory tests including liver function parameters were also performed. Skin tests (SPT and ID) with sulfamethoxazole and trimethoprim were repeated at the previously referred concentrations, followed by ultraviolet (UV) photopatch tests (UltraVitalux 300W quartz lamp, Osram , Madrid) with both drugs individually [trimethoprim 32 mg/ml (10% petrolatum) and sulfamethoxazole 100 mg/ml (10% petrolatum)] according to the European Academy of Dermatology and Venereology recommendations. Drug challenge and drug desensitization were performed. Finally SPT, ID, and UV photopatch tests were repeated six months after the completion of treatment. The patient showed negative SPT and ID with the tested drugs. Blood test revealed normal white blood cell count with mild lymphocytosis without eosinophilia; C-reactive protein and liver function studies were both normal. The working diagnosis was photo-induced, delayed drug reaction due to the clinical history. Thus, photopatch tests were performed which turned out to be negative. Drug challenge test with cotrimoxazole was performed, achieving a total dose of 600/120 mg of trimethoprim/sulfamethoxazole, respectively. The patient showed immediate good tolerance, but developed intense facial rash two hours after the final dose. Cotrimoxazole became the only oral available antimicrobial to treat the severe and recurrent reaction of our patient, allowing him to maintain his normal activities and avoiding a long-term hospitalization as well; hence, drug desensitization to cotrimoxazole was indicated and performed using the protocol described in Table 1. The final dose of cotrimoxazole was reached and maintained for the next three months, without any adverse reaction. The patient showed also a good tolerance to sun exposure during the treatment. Six months after completion of the treatment, SPT and ID remained negative, but the photopatch test with trimethoprim was positive.

Induction of tolerance to different types of fish through desensitization with hake.

Food allergy is a health concern causing an important impact in patients quality of life (1) and on that of their families, due to the continuous monitoring required in order to avoid the allergen and the risk of potentially fatal reactions resulting from the accidental ingestion of the allergenic food. Fish is one of the main causes of food allergies in children (2), and, unlike other infant food allergies such as allergies to cow milk or eggs, fish allergy tends to persist over time (3). Even the inhalation of steam generated while cooking the allergenic food can also trigger allergic reactions, hence affecting the quality of life of these patients (4). This article is protected by copyright. All rights reserved.

Is the performance of ImmunoCAP ISAC 112 sufficient to diagnose peach and apple allergies

Food allergies constitute a public health issue, with a reported overall estimated prevalence of 6% in Europe1 and Rosacea as the main allergenic fruits among adults.2 The commercial microarray ImmunoCAP ISAC 112 (Thermofisher, Uppsala, Sweden) is a semiquantitative and reproducible in vitro diagnostic tool used for the determination of specific IgE (sIgE).3 However, its panel of allergens does not have the best accuracy when it comes to determining fruit allergies in the Mediterranean area: the inclusion of the thaumatinlike protein (TLP) Pru p 2 or the apple lipid transfer protein (LTP) Mal d 3 has been proposed to improve the diagnosis of peach4 and apple5 allergies, respectively, in the Mediterranean basin. We sought to determine the usefulness of a component-resolved microarray for the diagnosis of peach and apple allergies in the Mediterranean area.

Performance of component resolved microarray diagnosis in nuts allergy

Performance of commercially available component resolved microarray has not been widely evaluated in food allergy. Nut allergy is a prevalent and increasing food allergy in which component resolved diagnosis is crucial. In the context of a multicentric study on pollen and vegetable food allergy in Spain, we enrolled patients (n=100) who had suffered at least two episodes of immediate symptoms after ingestion of nuts (peanut, walnut or hazelnut). Skin prick test was positive for the corresponding nut. ImmunoCAP ISAC 112 was analyzed in all patients and ImmunoCAP to the available components from the studied sources were analyzed (Ara h 1, Ara h 2, Ara h 3 and Ara h 8 and Ara h 9, Jug r 1, Jug r 3, Cor a 1, Cor a 8, Cor a 9, Cor a 14) in those patients showing negative result to ISAC. Among the 67 patients allergic to peanut 3 were sensitized to Ara h 1, 3 to Ara h 2, 1 to Ara h 3, 9 to Ara h 6, 1 to Ara h 8 and 36 to Ara h 9. Twenty-seven peanut allergic patients showed no sensitization to any components in the microarray. Among these 27 ISAC negative peanut allergic patients, 3 were sensitized to Ara h 1, 1 to Arah 2, 1 to Ara h 3, 1 to Ara h 8 and 23 to Ara h 9 by CAP. Among the 69 patients allergic to walnut 7 were sensitized to Jug r 1, 6 to Jug r 2 and 45 to Jug r 3. Eighteen walnut allergic patient showed no sensitization to any component in the microarray. Among these 18 ISAC negative walnut allergic patients, 10 were sensitized to Jug r 3 by CAP (none to Jug r 1). Among the 56 patients allergic to hazelnut one was sensitized to Cor a 1, 33 to Cor a 8 and 2 to Cor a 9. Twenty hazelnut allergic patient showed no sensitization to any components in the microarray. Among these 20 ISAC negative hazelnut allergic patients, 10 were sensitized to Cor a 8 by CAP (none to Cor a 1, Cor a 9 or Cor a 14). Among the 100 patients allergic to peanut, walnut or hazelnut, 40 patients did not show specific IgE against the studied nuts/ components in ISAC. Only a sixty per cent of the patients allergic to nuts (peanut, walnut or hazelnut) are diagnosed by ISAC. Sensitization to the lipid transfer proteins Ara h9, Jug r 3 and Cor a 8 was not detected by ISAC but it was recovered by CAP analysis.