Misdiagnosis trends in patients with hereditary angioedema from the real-world clinical setting

BACKGROUND

Hereditary angioedema due to C1 inhibitor deficiency (C1-INH-HAE) causes swelling in the skin and upper airways and pain in the abdomen because of mucosal swelling. C1-INH-HAE is frequently misdiagnosed, leading to delays in diagnosis, inadequate treatment, and unnecessary procedures.

OBJECTIVE

To evaluate the history of misdiagnosis in patients participating in the Icatibant Outcome Survey (IOS).

METHODS

The IOS is an observational study in which safety and effectiveness of icatibant have been evaluated since 2009. As part of the IOS, patients record any misdiagnoses received before being diagnosed as having C1-INH-HAE.

RESULTS

In January 2016, a total of 418 of 633 IOS patients with C1-INH-HAE type I or II had provided misdiagnosis data. Of these, 185 of 418 (44.3%) received 1 or more prior misdiagnoses. The most common misdiagnoses were allergic angioedema (103 of 185) and appendicitis (50 of 185). A variety of other misdiagnoses were reported, including a substantial number of gastrointestinal disorders (excluding appendicitis). Misdiagnosis rates were similar between males (41.1%) and females (46.5%) and between C1-INH-HAE type I (43.7%) and type II (51.6%). Patients with family members diagnosed as having C1-INH-HAE were significantly less likely to be misdiagnosed than patients without a family history (140 of 366 [41.7%] vs 38 of 58 [65.5%], respectively; P = .001). Patients with a prior misdiagnosis had longer median delay to C1-INH-HAE diagnosis (13.3 years) than patients without (1.7 years; P < .001).

CONCLUSION

From this large database, approximately 50% of patients with C1-INH-HAE type I or II have previously had their conditions misdiagnosed, most commonly as allergic angioedema or appendicitis. Misdiagnosis results in marked delays in receiving the correct diagnosis, during which time patients cannot access effective, lifesaving treatment.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01034969.

Two cases of overlap severe cutaneous adverse reactions to benznidazole treatment for asymptomatic Chagas disease in a nonendemic country

Chagas disease is a parasitosis endemic to South America. It is normally treated with benznidazole as first choice, which has been associated with numerous cutaneous reactions. However, very few benznidazole-associated severe cutaneous adverse reactions have been reported to date. The rise of Chagas disease in nonendemic countries represents a growing public health challenge. We report two patients who met the criteria for drug reaction with eosinophilia and systemic symptoms syndrome and Stevens-Johnson syndrome/toxic epidermal necrolysis according to the RegiSCAR scoring systems. They were thus deemed overlapping cases, with a lymphocyte transformation test positive for benznidazole. Both required intensive care unit admission and both survived. Considering the rising application of this drug for trypanosomiasis in immigrant populations, clinicians should be aware of this newly reported, potentially life-threatening risk.

Management of angioedema without urticaria in the emergency department

Angioedema refers to a localized, transient swelling of the deep skin layers or the upper respiratory or gastrointestinal mucosa. It develops as a result of mainly two different vasoactive peptides, histamine or bradykinin. Pathophysiology, as well as treatment, is different in each case; nevertheless, the resulting signs and symptoms may be similar and difficult to distinguish. Angioedema may occur at any location. When the affected area involves the upper respiratory tract, both forms of angioedema can lead to an imminent upper airway obstruction and a life-threatening emergency. Emergency physicians must have a basic understanding of the pathophysiology underlying this process. Angioedema evaluation in the emergency department (ED) should aim to distinguish between histamine- and bradykinin-induced angioedema, in order to provide appropriate treatment to patients. However, diagnostic methods are not available at the ED setting, neither to confirm one mechanism or the other, nor to identify a cause. For this reason, the management of angioedema should rely on clinical data depending on the particular features of the episode and the patient in each case. The history-taking should be addressed to identify a possible etiology or triggering agent, recording complete information for an ulterior diagnostic study in the outpatient clinic. It is mandatory quickly to recognize and treat a potential life-threatening upper airway obstruction or anaphylaxis. This review focuses on the underlying mechanisms and management of histamine- and bradykinin-induced angioedema at the emergency department and provides an update on the currently available treatments.

Piperacillin-induced DRESS: distinguishing features observed in a clinical and allergy study of 8 patients

BACKGROUND

DRESS (drug reaction with eosinophilia and systemic symptoms) syndrome is characterized by fever, rash, eosinophilia, and multiorgan failure. Previous reports have described differences in clinical and laboratory findings of DRESS syndrome depending on the inducing drug. Piperacillin has been reported as the drug responsible for this syndrome in 3 patients.

OBJECTIVE

To analyze and describe the clinical, laboratory, and allergy study findings of piperacillin-induced DRESS.

PATIENTS AND METHODS

Retrospective case series of patients diagnosed with DRESS associated with piperacillin-tazobactam (Pip/Taz) according to the Kardaun diagnostic score criteria. Assessment of causality was established using the Spanish Pharmacovigilance System and the lymphocyte transformation test (LTT). The allergy study included skin and epicutaneous tests.

RESULTS

Eight patients were diagnosed with DRESS due to Pip/Taz (3 probable and 5 definite cases). Skin rash was observed in all cases and facial edema in 50%; the mean latency period was 18 days. Fever was present in 7 patients. Liver and kidney injuries were detected in 6 and 3 patients, respectively. All patients had eosinophilia and a full recovery. The LTT to Pip/Taz was strongly positive in all patients, with a stimulation index of over 6. Three of 3 patients had a positive intradermal test to Pip/Taz, and 1 of 4 had a positive patch test. All patients had a negative LTT to carbapenems.

CONCLUSIONS

We have reported on the first case series of piperacillin-induced DRESS. A latency period of 18 days, skin rash, eosinophilia, fever, liver injury, and good prognosis were the most common features. The allergy study, and the LTT in particular, was highly useful for identifying Pip/Taz as the culprit drug and piperacillin as the responsible active ingredient.

Proton pump inhibitors are associated with hypersensitivity reactions to drugs in hospitalized patients: a nested case-control in a retrospective cohort study

BACKGROUND

Previous research has shown that gastric acid suppression by antacid drugs can promote allergic reactions to acid-labile food proteins. No data are available about whether antacid drugs can promote drug hypersensitivity reactions. The most potent and longer lasting inhibition of gastric secretion is provided by proton pump inhibitors (PPIs). We hypothesized that gastric acid suppression by proton pump inhibitors could be causative of drug hypersensitivity reactions during hospitalization.

OBJECTIVE

To estimate the risk of developing drug hypersensitivity reactions during the hospitalization of patients treated with proton pump inhibitors, and other associated factors.

METHODS

A nested case-control in a retrospective cohort study of hospitalized patients from September 2008 to December 2010 (70 771 admissions) was conducted using the registry of cases of interconsultations to the Allergy Department (161 confirmed cases of drug hypersensitivity reactions). A total of 318 controls were matched by first drug suspected in the hypersensitivity reaction, time of admission, age, gender and hospitalization wards.

RESULTS

The relative risk of drug hypersensitivity reaction occurrence during hospitalization of patients treated with PPIs compared with those not treated in the period of study was significant (RR: 3.97; 95% CI: 1.97-8.29). After controlling for confounders in the nested case-control cohort, the use of PPIs persists as a predisposing factor (OR: 4.35; 95% CI: 2-9.45). Personal history of drug allergy and a long hospitalization time were other predisposing factors of drug hypersensitivity reactions (DHRs). The hazard that a DHR has occurred during PPI treatment was 3.7% per day. The hazard for immediate or accelerated reactions was 1.706 (P = 0.003) times that of delayed reactions.

CONCLUSION AND CLINICAL RELEVANCE

In hospitalized patients, the use of proton pump inhibitors was associated with a significant increase risk of drug hypersensitivity reactions along with a personal history of drug allergies and long hospitalization time.

Management of dental-oral procedures in patients with hereditary angioedema due to C1 inhibitor deficiency

BACKGROUND

Hereditary angioedema due to C1 inhibitor deficiency (HAE-C1-INH) has considerable implications for dental health care providers, since dental procedures may trigger severe and even life-threatening episodes. The aim of the present study was to analyze the efficacy and safety of premedication with attenuated androgens (AAs), plasma-derived human C1 esterase inhibitor concentrate (pdhC1INH), or both to prevent the development of upper airway angioedema after dental-oral procedures in patients with HAE-C1-INH.

MATERIAL AND METHODS

All dental-oral procedures performed on patients with HAE-C1-INH who were followed up at La Paz University Hospital, Madrid, Spain were reviewed. Demographic data, maintenance treatment, preprocedure prophylaxis, disease severity, and occurrence of upper airway angioedema were recorded.

RESULTS

Twenty-four patients (14 male/10 female; mean age, 42.6 years) underwent 66 procedures. Most procedures were performed on patients with severe HAE-C1-INH (20 procedures) or moderate HAE-C1-INH (26 procedures). Only 9 procedures were performed without short-term prophylaxis. Mild upper airway angioedema developed after 3 procedures performed without short-term prophylaxis in patients with minimal or asymptomatic HAE-C1-INH. A statistically significant association was found between development of mild postprocedure upper airway angioedema and lack of maintenance treatment with AA, lack of increased dose of preprocedure AA, and failure to administer preprocedure pdhC1INH (P = .002, Fisher exact test).

CONCLUSIONS

Increased doses of prophylactic AA, administration of pdhC1INH, or both were good options for ambulatory management of dental-oral procedures in patients with HAE-C1-INH. Prophylaxis with pdC1INH or increased doses of AA is advisable before dental-oral procedures, even in patients with low disease severity.

Expression of α-defensin 1-3 in T cells from severe cutaneous drug-induced hypersensitivity reactions

BACKGROUND

Cytotoxic T cells seem to be the main effector cells in Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN). However, recent data support a role of the innate immune system in the etiopathology of drug-induced cutaneous reactions. In this study, we analyzed the expression of α-defensins 1-3 in mononuclear cells from patients with SJS/TEN, drug-induced maculopapular exanthema (MPE), and healthy donors.

METHODS

DEFA1A3 gene expression was analyzed by quantitative and end-point RT-PCR. Intracellular flow cytometry, immunofluorescence and immunohistochemistry were carried out to verify α-defensin 1-3 protein expression in mononuclear cells from peripheral blood and skin infiltrates. α-Defensin 1-3 concentration was evaluated in plasma and blister fluid samples by ELISA.

RESULTS

We herein describe DEFA1A3 gene expression in peripheral blood mononuclear cells (PBMCs) from patients with drug-induced cutaneous diseases. Gene expression analysis unveiled transcription in CD4 and CD8 peripheral blood T cells. Protein expression was confirmed by intracellular flow cytometry in mononuclear cells from the patients, including monocytes, NK cells, and T cells from peripheral blood and blister fluid. Further analysis of protein content by flow cytometry revealed higher protein levels in CD56(+) CD3(+) lymphocytes from patients with SJS/TEN when compared to MPE and healthy donors. Immunohistological analysis was used to confirm expression in dermal infiltrates. α-Defensin levels were estimated by ELISA to be 3- to 175-fold higher in blister fluid when compared to simultaneously drawn plasma samples.

CONCLUSION

Upregulation of innate immune molecules such as α-defensins 1-3 in T cells from patients with SJS/TEN may be involved in the etiopathology of these life-threatening diseases induced by medications.

Consensus statement on the diagnosis, management, and treatment of angioedema mediated by bradykinin. Part I. Classification, epidemiology, pathophysiology, genetics, clinical symptoms, and diagnosis

BACKGROUND

There are no Spanish guidelines or consensus statement on bradykinin-induced angioedema.

AIM

To review the pathophysiology, genetics, and clinical symptoms of the different types of bradykinin-induced angioedema and to draft a consensus statement in light of currently available scientific evidence and the experience of experts. This statement will serve as a guideline to health professionals.

METHODS

The consensus was led by the Spanish Study Group on Bradykinin-Induced Angioedema (SGBA), a working group of the Spanish Society of Allergology and Clinical Immunology. A review was conducted of scientific papers on different types of bradykinin-induced angioedema (hereditary and acquired angioedema due to C1 inhibitor deficiency, hereditary angioedema related to estrogens, angioedema induced by angiotensin-converting enzyme inhibitors). Several discussion meetings of the SGBA were held in Madrid to reach the consensus.

RESULTS

The pathophysiology, genetics, and clinical symptoms of the different types of angioedema are reviewed. Diagnostic approaches are discussed and the consensus reached is described.

CONCLUSIONS

A review of bradykinin-induced angioedema and a consensus on diagnosis are presented.

Consensus statement on the diagnosis, management, and treatment of angioedema mediated by bradykinin. Part II. Treatment, follow-up, and special situations

BACKGROUND

There are no previous Spanish guidelines or consensus statements on bradykinin-induced angioedema.

AIM

To draft a consensus statement on the management and treatment of angioedema mediated by bradykinin in light of currently available scientific evidence and the experience of experts. This statement will serve as a guideline to health professionals.

METHODS

The consensus was led by the Spanish Study Group on Bradykinin-Induced Angioedema, a working group of the Spanish Society of Allergology and Clinical Immunology. A review was conducted of scientific papers on different types of bradykinin-induced angioedema (hereditary and acquired angioedema due to C1 inhibitor deficiency, hereditary angioedema related to estrogens, angioedema induced by angiotensin-converting enzyme inhibitors). Several discussion meetings were held to reach the consensus.

RESULTS

Treatment approaches are discussed, and the consensus reached is described. Specific situations are addressed, namely, pregnancy, contraception, travelling, blood donation, and organ transplantation.

CONCLUSIONS

A review of and consensus on treatment of bradykinin-induced angioedema is presented.

Use of the lymphocyte transformation test in the diagnosis of DRESS syndrome induced by ceftriaxone and piperacillin-tazobactam: two case reports

Drug-related rash with eosinophilia and systemic symptoms (DRESS) syndrome, or drug-induced hypersensitivity syndrome (DIHS), is a life-threatening multiorgan systemic reaction characterized by rash, fever, lymphadenopathy, hepatitis, and leukocytosis with eosinophilia. Aromatic anticonvulsant drugs and allopurinol have been reported to be the most frequent eliciting agents. Our search of the literature revealed only 2 cases induced by piperacillin and 1 case by ceftriaxone.We present 2 cases of DRESS syndrome induced by the beta-lactam drugs ceftriaxone and piperacillin-tazobactam. An allergological workup including skin prick test, intradermal tests, patch tests, and lymphocyte transformation test (LTT) was performed. LTT was shown to be a useful technique in both cases to help to identify the drugs involved.

Associations among pollen sensitizations from different botanical species in patients living in the northern area of Madrid

OBJECTIVE

To determinate the existence of associations among sensitizations to antigens produced by pollen grains of different botanical species as assessed by skin prick tests in patients with respiratory disorders.

METHODS

Six hundred twenty nine consecutive patients living in the northern area of Madrid who underwent clinical evaluation because of rhinoconjunctivitis, and/or asthma were studied. All patients were tested with a skin prick test using a battery of inhalants including pollens, dust mites, molds and danders. The exploratory multivariate technique of Multiple Correspondence Analysis was used to compare the homogeneity of sensitizations between groups. Of the 629 patients, 459 (73.0%) had positive skin prick tests to pollen and were selected as the study group.

RESULTS

The most prevalent pollen sensitization was to Gramineae pollen (83.7%) followed by Oleaceae sensitisation (75.8%). Multiple Correspondence Analysis revealed the existence of an association among pollen sensitizations, showing that they clustered two groups: sensitizations to Gramineae, Oleaceae, Cupressaceae, Chenopodiaceae, Plantaginaceae (group I), and sensitizations to Betulaceae, Platanaceae, Compositae (group II). Sensitization to Parietaria was not included in any of the sensitization groups and showed an independent behaviour.

CONCLUSION

Pollen sensitizations in our area cluster into two association groups which have not previously been reported.

Gastroallergic anisakiasis: findings in 22 patients

BACKGROUND AND AIMS

Ingestion of Anisakidae larvae in raw seafood may cause anisakiasis. However, despite the high level of consumption of seafood in Spain, only a few cases of anisakiasis have been reported until now. Anisakis simplex can cause allergic reactions in sensitized patients as a result of its parasitism in the gastrointestinal tract. The purpose of this study was to analyse the clinical findings in 22 patients with gastroallergic anisakiasis.

METHODS

Patients with allergic and/or gastric symptoms after seafood ingestion were evaluated in the emergency room of the La Paz General University Hospital. Skin testing for Anisakis simplex and tests on the implicated seafood were performed and amounts of serum-specific immunoglobulin E were assessed. A gastroscopy was performed in those patients with severe allergic or/and persistent gastric symptoms after ingestion of raw or undercooked seafood.

RESULTS

Twenty-two patients were diagnosed with gastroallergic anisakiasis in 1 year. Most patients presented to the emergency room of our hospital with allergic symptoms. Gastric symptoms were usually moderate. Gastroscopy revealed local mucosal oedema and gastric erosion at the point of fixation. Two or more worms were detected in three patients. The mean time of latency of allergic symptoms was 5 h, while the mean time for gastric symptoms was 3 h.

CONCLUSION

Anisakis simplex parasitism was the causative agent of allergic and gastric symptoms. Gastroallergic anisakiasis appears to be a relatively common disease, that may have been underdiagnosed.

Importance of albumin in cross-reactivity among cat, dog and horse allergens

Different allergenic proteins have been involved in cross-reactivity among animals. Albumins seem to be cross-sensitizing allergenic components. The aim of this study was to assess the importance of albumin as a cross-reactive allergen in patients sensitized to cat, dog and horse. One hundred and seventeen patients sensitized to cat were tested for IgE reactivity using skin prick tests and RAST assays with cat, dog and horse hair/dander extracts and their purified albumin extracts. RAST-inhibition studies were carried out to assess cross-reactivity among cat, dog and horse and among their purified albumins. It was found that 22% of patients exhibited specific IgE to cat albumin; 41% of patients sensitized to cat were also sensitized to dog and horse. Out of these patients, 21% had IgE to three albumins and 17% to two. Reciprocal inhibitions were observed among cat, dog and horse albumins and also among cat, dog and horse hair/dander extracts, using in the latter experiment sera from patients not sensitized to albumins. IgE binding to horse extract was inhibited 30% by its homologous albumin and IgE binding to cat and dog extracts in almost 15% by their respective albumins. It was concluded that albumins from these three animals share some epitopes that account for the cross-reactivity observed in around one-third of patients sensitized to cat, dog and horse. Nevertheless, more than 50% of specific IgE that cross-reacts among these three animals is directed to allergens other than albumin.

Gastroallergic anisakiasis: borderline between food allergy and parasitic disease-clinical and allergologic evaluation of 20 patients with confirmed acute parasitism by Anisakis simplex

BACKGROUND

Human subjects can be parasitized by Anisakis simplex by eating raw or undercooked fish. Gastric anisakiasis is probably the most frequent clinical entity presenting with severe epigastric pain, vomiting, and diarrhea. In gastroallergic anisakiasis hypersensitivity symptoms predominate.

OBJECTIVE

We sought to describe clinical features, laboratory data, and gastroscopic findings in gastroallergic anisakiasis.

METHODS

We selected 40 patients presenting to the emergency department with an acute allergic reaction, and if we suspected acute parasitism by A simplex, a fiberoptic gastroscopy was performed. In 20 patients we could detect one or more nematodes; these patients are referred to as group A. Those in whom no worm could be found are referred to as group B (n = 20). A detailed history, clinical features, gastroscopic findings, laboratory data, and skin prick test responses were compared.

RESULTS

Long-time intervals of up to 26 hours between fish intake and onset of hypersensitivity symptoms were found (group A, 5.4 +/- 6.3 hours; group B, 5.3 +/- 2.6 hours). Patients in groups A and B did not differ with respect to allergic symptoms (urticaria, angioedema, erythema, bronchospasm, and anaphylaxis) or the mainly light abdominal symptoms (upper abdominal pain, nausea, vomiting, and diarrhea). No significant differences were found with respect to age, time interval between fish intake and onset of symptoms, white cell and eosinophil counts, specific IgE levels against A simplex, or total IgE levels.

CONCLUSIONS

The peculiar sometimes long-time interval between fish intake and onset of allergic symptoms render the diagnosis difficult. An early gastroscopy can confirm the diagnosis and prevent complications. We suggest that gastroallergic anisakiasis be considered a distinct clinical entity in which the predominant symptoms are hypersensitivity symptoms and in which the correct diagnosis is not only important in the management of the acute reaction but also in the prevention of further allergic episodes.

Erythema multiforme from betalactams with positive cutaneous tests

We report the case of a woman who after taking ampicillin and amoxicillin developed two severe cutaneous reactions with generalized erythema and maculopapular rash, which later turned into blisters with subsequent desquamation. She was clinically diagnosed with erythema multiforme syndrome after positive delayed cutaneous tests with benzylpenicillin, amoxicillin and ampicillin allowed for a more specific diagnosis. There are very few references to patients with drug reactions to betalactams who have positive skin prick or intradermal test but show delayed hypersensitivity, as was the case in our patient.

Delayed hypersensitivity to enoxaparin

A 65-year-old woman experienced immediate itchy erythematous patches at the subcutaneous injection sites of sodium enoxaparin. An erythematous and infiltrated 40 x 20 mm lesion on the abdominal wall could be observed at the site of enoxaparin injection when she was referred to our clinic 48 h after injection. Lesions subsided spontaneously within 1 week. She had been on this treatment 1 and 3 years before without any adverse reaction. To clarify the nature of the reaction, epicutaneous tests with sodium enoxaparin, calcium nadroparin and calcium heparin were performed, all with negative results. Skin prick test with sodium enoxaparin was also negative. Biopsy of the cutaneous lesion showed spongiotic dermatitis, strongly suggesting a delayed hypersensitivity mechanism. We report here on a new case of delayed hypersensitivity to enoxaparin. Being female, overweight and having prolonged application of the drug were suggested risk factors present in our patient. Biopsy was essential for diagnosis. Although type IV hypersensitivity reactions to enoxaparin are rare, we should start to suspect this condition in order not to underdiagnose it.

Hypersensitivity pneumonitis related to a covered and heated swimming pool environment

Hypersensitivity pneumonitis (HP) or extrinsic allergic alveolitis is a lung disease caused by a large group of inhaled antigens of various sources. The most common HP occurring in the farm environment is classically caused by exposure to various thermophilic actinomycetes and fungi that can grow in the farm environment. Pullularia species and thermophilic actinomycetes have been involved in HP related to humidifier water and saunas. Our case illustrates the value of a site visit in the diagnosis of HP. During a visit to the covered and heated swimming-pool where our patient used to swim we could see that favourable conditions to fungal growth existed. To determine the possible aetiological agents of a suspected HP, cultures from several parts of the swimming-pool were taken. These cultures showed an intense growth of thermophilic actinomycetes, Neurospora and Aspergillus species. Precipitating antibodies against Neurospora species and Mycropolyspora faeni were detected. A case of HP related to a covered and heated swimming-pool environment is reported. Thermophilic actinomycetes and Neurospora species may be the causing agents.

Allergic reactions to anisakis simplex parasitizing seafood

BACKGROUND

The ingestion of Anisakidae ssp larvae parasitized fish can cause anisakiasis. Allergic reactions after ingestion of safely cooked but parasitized fish have been reported.

METHODS

Twenty-three patients who suffered allergic reactions after seafood ingestion, with negative skin tests were studied. Anisakis simplex sensitization was assessed by skin prick test and/or specific serum Immunoglobulin E (IgE). Total serum IgE and specific IgE against the implicated seafood and Ascaris lumbricoides were also determined.

RESULTS

Manifestations of Anisakis simplex allergy were urticaria/angioedema (18/23) patients and anaphylaxis (5/23). Gastric symptoms were also observed (3/23). Sea fish and shellfish were implicated. Raw and cooked seafood ingestion caused reactions. Total serum IgE ranged from 13 to 7200 KU/L. Specific IgE to Anisakis simplex was positive (> 0.35 KU/L) in all patients, and skin tests were positive in 20. Serum-specific IgE and skin tests to the involved seafoods were negative in every patient. Serum-specific IgE to Ascaris lumbricoides was negative in 13 patients. No association between total IgE and the eosinophil count (r < 0.1) was observed, but there was some association between total IgE and specific IgE to Anisakis simplex (r = 0.58).

CONCLUSION

Anisakis simplex sensitization is the cause of allergic reactions after seafood ingestion. It is important to pay attention to this new "food allergy" to diagnose correctly the etiology of adverse food reactions.

Allergic contact reactions due to phenylephrine hydrochloride in eyedrops

BACKGROUND

Dermatitis of and around the eye is common. Allergic contact reactions from phenylephrine are rare despite extensive use by ophthalmologists. Previous reports do not indicate crossreactivity between phenylephrine and other sympathomimetic drugs in patch testing.

METHODS

We report three cases of allergic contact reactions (dermato-conjunctivitis) after eyedrops. Skin prick tests, epicutaneous testing with the implicated drugs, additives, and a complete patch test battery, TRUE test (Upjohn-Pharmacia, Sweden), were performed in each patient.

RESULTS

All skin prick tests were negative. The three patients showed positive patch tests to phenylephrine and one of them also to ephedrine. Tolerance of the other eyedrops without phenylephrine was verified by challenge.

CONCLUSION

Phenylephrine was the responsible agent for the reactions in our patients as confirmed by clinical findings and positive patch tests. Our findings suggest the central structure as the sensitizing part of drug in the second patient. Patch testing is essential for diagnosis of allergic contact reactions of and around the eye.

Two cases of specific adverse reactions to systemic corticosteroids

Although true allergic reactions due to systemic corticosteroid therapy are not frequent, they should be kept in mind since allergic reactions to this kind of therapy are possible. We report two cases of specific adverse reactions resulting from systemic corticosteroid therapy which were diagnosed by provocation tests. The corticosteroids involved in each case were paramethasone and betamethasone, and methyl-prednisolone in both of them. Additives and other corticosteroids were studied by skin tests and challenges, with negative results. The structures of paramethasone and betamethasone are similar, with a 16 carbon methyl group in both, and with a fluoride in the alpha position of the 6 carbon in paramethasone, and a fluoride in the beta position of the 9 carbon and a 6 carbon methyl group in betamethasone. Methyl-prednisolone differs from that of other corticosteroids in its 6 carbon methyl group. We report two cases of specific adverse reactions caused by corticosteroids. Positive challenge tests showed a possible immunologic hypersensitivity mechanism in both cases. The patients' reactions demonstrated cross-reactivity between methyl-prednisolone and the corticosteroids having a 16 carbon methyl group, and fluoride or methyl radicals on the 6 carbon.

Delayed hypersensitivity to beta-lactams

We present nine patients with delayed allergic reactions to beta-lactams. Four of them developed reactions to ampicillin; the diagnostic studies suggested the involvement of a type IV hypersensitivity mechanism to an antigenic determinant in the side-chain structure, with intradermal and patch tests positive to ampicillin but good tolerance to benzylpenicillin. Three patients showed delayed hypersensitivity reactions to benzylpenicillin (positive delayed skin tests and/or challenges). Arthus-type reactions were seen in two other patients. Specific IgE of uncertain relationship to benzylpenicillin and ampicillin was later detected in four cases.

Synovial chondrometaplasia of the temporomandibular joint: report of case

A case of synovial chondrometaplasia of the temporomandibular joint is presented with a discussion of the pathologic findings, diagnosis, and treatment. This is a highly uncommon, benign lesion of this joint that affects women more often than men. Since the histologic appearance of some of the tissue cells may resemble malignant changes, care should be taken not to confuse this condition with chondrosarcoma.