Nonirritant intradermal skin test concentrations of ciprofloxacin, clarithromycin, and rifampicin

BACKGROUND

Intradermal skin testing of the clinically important antibiotics ciprofloxacin, clarithromycin, and rifampicin in the case of suspected allergies to antibiotics is poorly standardized. For clinical practice, standardized procedures and protocols are desired.

METHODS

Fifteen healthy volunteers were tested with different concentrations of the antibiotics as well as with appropriate controls. Test readings included wheal area measured by digital image analysis and blood flow increase measured by laser Doppler flowmetry (LDF). To reduce interpersonal variability, test results were normalized with the individual controls using a novel protocol.

RESULTS

Nonirritating concentrations of the three antibiotics (ciprofloxacin ~0.0067 mg/ml, clarithromycin ~0.05 mg/ml, rifampicin ~0.002 mg/ml) could be defined for healthy volunteers. Laser Doppler flowmetry generates comparable results to wheal area measurement. Normalization of the test results is necessary and can be applied in a practical algorithm.

CONCLUSIONS

Standardized skin testing to detect sensitization to broadly used nonbetalactam antibiotics was presented and should be applied in truly sensitized patients. This approach should help to minimize the inter- and intraindividual differences in reactivity.

Contact dermatitis to para-phenylenediamine in hair dye following sensitization to black henna tattoos - an ongoing problem

BACKGROUND

The increased frequency of case reports of allergic contact dermatitis from non-permanent black henna tattoos in recent years shows the popularity of this form of body painting.

PATIENTS AND METHODS

Seven patients presented with allergic contact dermatitis after initial hair or eyelash dyeing. They all had a history of a previous reaction from a black henna tattoo. All were patch tested with the European standard patch test series and the standard supplemental series, as well as special series for dyes and hairdressers.

RESULTS

All seven patients showed a positive reaction in patch testing with para-phenylenediamine (PPD) (0.3 % and/or 1.0 % in pet.). Five patients also had positive reactions to other dyes such as aminophenol, para-toluene diamine, disperse orange and yellow and four patients reacted to benzocaine. These were interpreted as cross-reactions. The time from sensitization by the black henna tattoo to the onset of allergic contact dermatitis after hair dyeing was an average of 6.2 years.

CONCLUSIONS

The most common cause of allergic contact dermatitis after black henna tattoos is PPD. Both the long skin contact and the high concentrations of PPD increase the risk of sensitization. Allergic contact dermatitis may be followed by post-inflammatory hyper- or hypopigmentation, scarring and lifelong sensitization, which can have occupational impact, especially for hair dressers and cosmeticians.

Analysis of an unusual cluster of systemic reactions to subcutaneous specific immunotherapy with respiratory allergens in one allergy center

Systemic reactions to subcutaneous immunotherapy occur despite all necessary precautions and experienced staff and should prompt a search for causative factors. We present an analysis of 11 reactions, 8 of them within a short period. The patients and reactions were evaluated regarding extract errors (composition, concentration), dosing errors, ignored contraindications to specific subcutaneous immunotherapy, introductions versus maintenance phase and accidental intravascular injection. No single or common cause could be identified. Statistical analysis suggests that exceptional clusters of systemic reactions such as these may be just random cumulations without identifiable cause.

A genome-wide meta-analysis of genetic variants associated with allergic rhinitis and grass sensitization and their interaction with birth order

BACKGROUND

Hay fever or seasonal allergic rhinitis (AR) is a chronic disorder associated with IgE sensitization to grass. The underlying genetic variants have not been studied comprehensively. There is overwhelming evidence that those who have older siblings have less AR, although the mechanism for this remains unclear.

OBJECTIVE

We sought to identify common genetic variant associations with prevalent AR and grass sensitization using existing genome-wide association study (GWAS) data and to determine whether genetic variants modify the protective effect of older siblings.

METHOD

Approximately 2.2 million genotyped or imputed single nucleotide polymorphisms were investigated in 4 large European adult cohorts for AR (3,933 self-reported cases vs 8,965 control subjects) and grass sensitization (2,315 cases vs 10,032 control subjects).

RESULTS

Three loci reached genome-wide significance for either phenotype. The HLA variant rs7775228, which cis-regulates HLA-DRB4, was strongly associated with grass sensitization and weakly with AR (P(grass) = 1.6 × 10(-9); P(AR) = 8.0 × 10(-3)). Variants in a locus near chromosome 11 open reading frame 30 (C11orf30) and leucine-rich repeat containing 32 (LRRC32), which was previously associated with atopic dermatitis and eczema, were also strongly associated with both phenotypes (rs2155219; P(grass) = 9.4 × 10(-9); P(AR) = 3.8 × 10(-8)). The third genome-wide significant variant was rs17513503 (P(grass) = 1.2 × 10(-8); PAR = 7.4 × 10(-7)) which was located near transmembrane protein 232 (TMEM232) and solute carrier family 25, member 46 (SLC25A46). Twelve further loci with suggestive associations were also identified. Using a candidate gene approach, where we considered variants within 164 genes previously thought to be important, we found variants in 3 further genes that may be of interest: thymic stromal lymphopoietin (TSLP), Toll-like receptor 6 (TLR6) and nucleotide-binding oligomerization domain containing 1 (NOD1/CARD4). We found no evidence for variants that modified the effect of birth order on either phenotype.

CONCLUSIONS

This relatively large meta-analysis of GWASs identified few loci associated with AR and grass sensitization. No birth order interaction was identified in the current analyses.

Metalworking exposures and persistent skin symptoms in the ECRHS II and SAPALDIA 2 cohorts

BACKGROUND

Diseases of the skin are important and often preventable conditions occurring among workers with dermal exposures to irritant and sensitizing agents.

OBJECTIVE

We conducted this analysis to assess the associations between metalworking exposures and current and persistent skin symptoms among male and female participants in two population-based epidemiologic studies.

METHODS

We pooled data from the European Community Respiratory Health Survey II (ECRHS II) and the Swiss Cohort Study on Air Pollution and Lung and Heart Disease in Adults 2 (SAPALDIA 2), two prospective cohort studies in Europe. Each participant completed interviewer-administered questionnaires to provide information about symptoms and exposures related to selected occupations, including metalworking, during the follow-up periods. We assessed associations between skin symptoms and the frequency of metalworking exposures among 676 ECRHS II/SAPALDIA 2 respondents.

RESULTS

Current skin symptoms were reported by 10% of metalworkers and were associated with frequent use, defined as four or more days per week, of oil-based metalworking fluids [prevalence ratio (PR): 1.76, 95% confidence interval (CI): 1.25-2.49)] and organic solvent/degreasing agents (PR: 2.06, 95% CI: 1.21-3.50).

CONCLUSIONS

Skin symptom prevalence is associated with increasing frequency of oil-based metalworking fluid and degreasing agent use. Our findings justify assessing strategies for reducing the frequency of metal-related exposures.

Safety profile of hymenoptera venom immunotherapy (VIT) in monosensitized patients: lack of new sensitization to nontreated insect venom

BACKGROUND

Venom immunotherapy (VIT) has proven to be efficacious in reducing the severity of anaphylactic reactions following field stings in patients with Hymenoptera venom allergy. Due to sequence homologies in the allergens used in Hymenoptera vaccines, there is concern that immunotherapy could lead to sensitization to allergens to which patients were not previously sensitized. The relevance of such an undesired phenomenon is unclear.

OBJECTIVES

To investigate the incidence of sensitization to Hymenoptera venoms other than those to which the patients were already sensitized and to assess the overall safety profile of VIT in order to compare the risk-benefit ratio in a subpopulation of monosensitized individuals.

METHODS

We performed a retrospective analysis of specific immunoglobulin E (sIgE) levels in patients with no prior detectable sIgE to Hymenoptera venom other than the one for which they received VIT. We assessed the safety profile of VIT using serological and clinical parameters.

RESULTS

Of the 56 monosensitized patients who had VIT, 3 (5%) developed sIgE to the other insect with no history of field sting to explain it. This rate was similar to the rate of new sensitization due to field stings during VIT. VIT was well-tolerated and levels of serological markers improved. No patient had a systemic anaphylactic reaction after having been stung by an insect other than the one he/she was desensitized for during follow-up.

CONCLUSION

VIT seems to be safe with respect to clinically significant new sensitizations.

The role of iodine in hypersensitivity reactions to radio contrast media

INTRODUCTION

Hypersensitivity reactions to iodinated radio contrast media (RCM) are either immediate-type (IT) or delayed reactions (DT). In IT, the pathomechanism is unclear. In DT, delayed positive patch (PT) and intradermal tests (IDT) and RCM-specific T cells suggest a T cell-mediated mechanism. In both, the role of iodine has not been clarified; however, patients are often labelled as 'iodine allergic'. Occasionally, positive skin tests to iodine-containing drugs are observed.

OBJECTIVE

We investigated the presence of hypersensitivity to iodine in patients with a history of hypersensitivity reactions to RCM.

METHODS

Nineteen patients with a history of IT (n=9) or DT (n=10) to RCM were investigated. Skin prick tests, IDT and PT with several RCM and iodine formulations were carried out. All underwent oral provocation with Lugol's solution (LS). Two patients each with iodine mumps, contact dermatitis to iodized antiseptics and chronic idiopathic urticaria served as control or proof of concept.

RESULTS

In the IT group, skin tests were positive in three out of nine patients to one RCM. One patient with negative skin tests reacted twice to oral iodine with urticaria. In the DT group, sensitization to one or several RCM was identified in 10 out of 10 patients. In seven out of 10 patients, additional sensitizations to the iodine formulations were found. Two patients developed a mild exanthema after oral provocation with LS.

CONCLUSION

We have previously demonstrated in patients with iodine mumps that an oral challenge with LS is a valid means to elicit hypersensitivity reactions to iodine. In 19 patients, we showed that iodine is rarely the eliciting agent in hypersensitivity reactions to RCM. Only one patient with a late urticaria to an RCM with a late urticaria to LS and two patients with DT and broad sensitization to all RCM tested reacted to LS with an exanthema. In most cases, more likely the RCM molecules and not iodine are the eliciting compounds.

Danger signs in drug hypersensitivity

ADRs are frequently considered iatrogenic complications and, therefore, pose a specific challenge for the physician-patient relationship. Early recognition of a potential ADR is possible, especially on the skin, in addition to characteristic clinical danger signs. Cutaneous manifestations are variable, depending on the causative pathomechanism. It is impossible to conclude the causative agent from the morphology of the cutaneous lesions. The intake of several drugs in the time before the elicitation of the drug reaction usually poses a diagnostic challenge. It is crucial for the precision of any further allergological work-up to document the type of rash precisely as well as the time course of drug intake and appearance of the first symptoms. involvement of internal organs or circulating blood cells. Timely recognition of such cutaneous lesions and the correct differential diagnosis with prompt withdrawal of the putative culprit drug are essential to reducing morbidity and preventing mortality. This article discusses risk factors, early symptoms, and danger signs indicating a possibly severe course of an ADR and advises on early actions.

Delayed cutaneous manifestations of drug hypersensitivity

Drugs may elicit a considerable variety of clinical signs, often affecting the skin and the mucous membranes. The most common are maculopapular exanthemas and urticaria, more rarely pustules, bullae vasculitic lesions, and lichenoid lesions may also be observed. Apart from the morphology, the chronology of the occurrence and the evolution of single skin lesions and exanthema are also paramount in the clinical diagnosis of cutaneous drug hypersensitivity. Often, the skin represents the only organ manifestation; however, it may be the herald for a systemic involvement of internal organs, such as in severe drug-induced hypersensitivity syndromes or anaphylaxis.

Adverse drug reactions to biologics

The use of biologics has rapidly expanded since the introduction of the first diagnostic antibodies; they are now widely employed in oncology, autoimmune disorders, inflammatory diseases and transplantation medicine. Their widespread use has resulted in an increase in adverse drug reactions. Adverse effects result from both direct pharmacological actions and immunological actions, as well as through induction of a specific immune response. The nomenclature, particularly of the monoclonal antibodies, identifies the target structure and organ as well as the species of origin, which then helps predict their effects and antigenic properties. Depending on the extent of foreign protein, anti-allotypic or anti-idiotypic antibodies with or without neutralizing properties may be induced. Adverse drug reactions from biologics often depend on the target and may be explained by activation or inhibition of particular cytokine pathways. Adverse drug reactions are classified by their pathomechanism, which enhances understanding of the pathogenesis and facilitates both allergologic diagnostic measures and planning of premedication in future treatments. This review emphasizes immunostimulatory and hypersensitivity reactions.

Processing-dependent and -independent pathways for recognition of iodinated contrast media by specific human T cells

BACKGROUND

One to three percent of patients exposed to intravenously injected iodinated contrast media (CM) develop delayed hypersensitivity reactions. Positive patch test reactions, immunohistological findings, and CM-specific proliferation of T cells in vitro suggest a pathogenetic role for T cells. We have previously demonstrated that CM-specific T cell clones (TCCs) show a broad range of cross-reactivity to different CM. However, the mechanism of specific CM recognition by T cell receptors (TCRs) has not been analysed so far.

OBJECTIVE

To determine how T cells specifically recognize CM.

METHODS

CM-specific TCCs were generated from human blood of three CM-allergic patients and a specific TCR was transfected into a mouse T cell hybridoma. Functional analysis such as proliferation assays, IL-2 secretion assays, and calcium influx experiments were performed using irradiated, glutaraldehyde-fixed, CM-pre-incubated, human leucocyte antigen (HLA)-DR-matched or -mismatched antigen-presenting cells (APCs), and HLA-blocking antibodies.

RESULTS

We identified two mechanisms of T cell stimulation: some TCCs and the transfectant reacted to CM independent of uptake by APCs because proliferation/IL-2 secretion occurred in the presence of glutaraldehyde-fixed APCs, and intracellular calcium increased within seconds after drug addition. Other TCCs required functional APCs, compatible with uptake and presentation of CM on MHC-class II molecules, as implied by three findings: (1) glutaraldehyde fixation of APCs abrogated presentation; (2) CM could not be washed away from CM-pre-incubated APCs; and (3) the optimal pulsing time was 10-20 h. Because allogeneic, MHC-matched, CM-pulsed APCs could induce proliferative responses as well, the ability of CM uptake and presentation is not unique to APCs from patients with CM-induced delayed hypersensitivity.

CONCLUSION

Our data suggest that CM may be stimulatory for T cells either by direct binding to the MHC-TCR complex or by binding after uptake and processing by APCs. This questions the assumed inert nature of CM.

Ectoparasites from feral pigeons affecting humans

Feral pigeons pose a considerable health risk to the human population. They are vectors of infectious diseases and source of antigens causing allergic diseases. Breeding and roosting sites of pigeons harbor parasites that may infest humans. In the present article, a concomitant parasitization of a young female with 3 different ectoparasites, the bedbug Cimex lectularius, the pigeon tick Argas reflexus and the red mite Dermanyssus gallinae, is reported. The parasites invaded the apartment from a balcony used as roost by feral pigeons and infested the patient continuously over a period of more than 2 months. To our knowledge this case presents the first record of a coincidental infestation of a single patient with several ectoparasite species deriving from feral pigeons. Additionally we report general symptoms in the patient probably caused by the high number of stings. Dermatologists should be aware of the possibility of an infestation with ectoparasites deriving from feral pigeons. In a review we give an overview on the most important ectoparasites transmitted from feral pigeons to humans and their importance for the dermatologist.

Hypersensitivity reactions to anticoagulant drugs

Drugs with anticoagulant activity, including heparins, hirudins, coumarins, and platelet aggregation inhibitors belong to the most widely used drugs. Hypersensitivity reactions from these agents are rare. However, due to their widespread use, they may have a considerable impact on patient safety and treatment. Accurate diagnosis of potentially life-threatening adverse events and identification of alternatives is mandatory. We review hypersensitivity reactions caused by the different groups of anticoagulant agents and discuss the pathophysiological mechanisms, diagnostic possibilities and management options. According to patients histories the most common hypersensitivity reaction is intolerance to acetylsalicylic acid (ASA). Also localized erythematous plaques, occurring to subcutaneous application of heparins are rather common. Other hypersensitivity reactions are rare but may be life-threatening, e.g. skin necrosis due to heparin-induced thrombocytopenia. Rarely anaphylactoid reactions have been observed to ASA, heparin, and hirudin. Skin and provocation tests with immediate and late readings are the most reliable diagnostic tools for heparin- or hirudin-induced urticaria/anaphylaxis or heparin-induced delayed plaques. Provocation tests may be used to identify safe alternatives. In cases of necrosis from heparins or coumarins, all in vivo tests are contraindicated. Most in vitro tests are not universally available, and with the exception of platelet aggregation tests, they have a low sensitivity. In some anticoagulant-associated hypersensitivity reactions detailed allergologic investigation may help to identify safe treatment alternatives. Typically, several tests are needed, and therefore the test procedures are time consuming.

Sensitisation to Ambrosia in Switzerland: a public health threat on the wait

BACKGROUND

Ambrosia artemisiifolia (short name = Ambrosia common ragweed) pollen is a potent allergen and has recently been found in Switzerland, spreading from the southwest of the country. The aim of this study is to describe Ambrosia sensitisation rates in the population-based SAPALDIA cohort (Swiss Study on Air Pollution And Lung Diseases In Adults) and to test whether an increase in these rates could be observed.

METHODS

Among the 6345 participants from 8 areas who provided blood samples in 1991 and 2002, 5823 had valid results for specific IgE against common inhalant allergens tested with Phadiatop. In 2002 Ambrosia sensitisation was measured and positive tests were analysed for Artemisia vulgaris (mugwort). Blood samples taken in 1991 in Ticino and Geneva were also tested for Ambrosia.

RESULTS

Sensitisation rate (Phadiatop) did not increase significantly between the two surveys and sensitisation was found in 30% of the participants. A proportion of 7.9% showed specific IgE to Ambrosia pollen. The sensitisation rate in Lugano and Geneva had not changed substantially since 1991. Among those sensitised to Ambrosia 82% also showed specific IgE against Artemisia, suggesting a high rate of cross-reactivity. Only 1.3% were sensitized to Ambrosia alone. The incidence of asthma or hay fever in participants with specific IgE to Ambrosia pollen was not higher than in the general study population.

CONCLUSION

Currently Ambrosia pollen does not appear to be an important cause of inhalant allergies in Switzerland. Sensitisation rates are low and have not increased since 1991. Due to cross-reactivity Ambrosia sensitisation may be a consequence of primary sensitisation to Artemisia. Elimination of Ambrosia plants is nevertheless mandatory to avoid a future increase.

Skin testing in patients with hypersensitivity reactions to iodinated contrast media - a European multicenter study

BACKGROUND

Iodinated contrast media cause both immediate and nonimmediate hypersensitivity reactions. The aim of this prospective study was to determine the specificity and sensitivity of skin tests in patients who have experienced such reactions.

METHODS

Skin prick, intradermal and patch tests with a series of contrast media were conducted in 220 patients with either immediate or nonimmediate reaction. Positive skin tests were defined according to internationally accepted guidelines. Seventy-one never-exposed subjects and 11 subjects who had tolerated contrast medium exposure, served as negative controls.

RESULTS

Skin test specificity was 96-100%. For tests conducted within the time period from 2 to 6 months after the reaction, up to 50% of immediate reactors and up to 47% of nonimmediate reactors were skin test positive. For immediate reactors, the intradermal tests were the most sensitive, whereas delayed intradermal tests in combination with patch tests were needed for optimal sensitivity in nonimmediate reactors. Contrast medium cross-reactivity was more common in the nonimmediate than in the immediate group. Interestingly, 49% of immediate and 52% of nonimmediate symptoms occurred in previously unexposed patients. Many of these patients were skin test positive, indicating that they were already sensitized at the time of first contrast medium exposure.

CONCLUSIONS

These data suggest that at least 50% of hypersensitivity reactions to contrast media are caused by an immunological mechanism. Skin testing appears to be a useful tool for diagnosis of contrast medium allergy and may play an important role in selection of a safe product in previous reactors.