Fixed drug eruption caused by iopamidol, a contrast medium

The Role of Patch Testing in Evaluating Delayed Hypersensitivity Reactions to Medications

Confirming drug imputability is an important step in the management of cutaneous adverse drug reactions (CADR). Re-challenge is inconvenient and in many cases life threatening. We review the literature on ideal patch testing technique for specific CADRs. Testing should be performed approximately 3 months after the resolution of the eruption using standard patch testing techniques. Commercially available patch test preparations are available for a minority of drugs, so in most cases, testing should be performed with the drug at various recommended concentrations and in different vehicles. Testing to all known excipients, such as dyes, vehicles and preservatives is also important. Immunosuppressive medications should be discontinued or down titrated to the lowest tolerable dose to decrease the risk of false negative reactions. We provide an overview of expert recommendations and extant evidence on the utility of patch testing for identifying the culprit drug in common CADRs and for specific drug or drug classes. Overall, there appears to be significant variability in the patch test positivity of different drugs, which is likely the result of factors intrinsic to the drug such as dermal absorption (as a function of lipophilicity and molecular size) and whether the drug itself or a downstream metabolite is implicated in the immune reaction. Drugs with high patch test positivity rates include beta-lactam antibiotics, aromatic anticonvulsants, phenytoin, and corticosteroids, among others. Patch testing positivity varies both as a function of the drug and type of CADR. The sum of the evidence suggests that patch testing in the setting of morbilliform eruptions, fixed drug eruption, acute generalized exanthematous pustulosis, and possibly also drug-induced hypersensitivity syndrome, photoallergic and eczematous reactions may be worthwhile, although utility of testing may vary on the specific drug in question for the eruption. It appears to be of limited utility and is not recommended in the setting of other complex CADR, such as SJS/TEN and leukocytoclastic vasculitis.

Fixed Drug Eruption due to Iopromide (Ultravist®)

A 69-year-old male presented with several painful erythematous patches on both palms and trunk several days after receiving iopromide (Ultravist®, Shering, Berlin, Germany). A fixed drug eruption (FDE) due to iopromide was suspected clinically. However, at that time, the patch test with iopromide at the lesion site gave negative results. Three years later, the patient was mistakenly administered iopromide again and patches with vesicles recurred on the same sites as well as on the genitalia. This episode was repeated once again after 1 year. In all episodes, the skin lesion resolved after application of topical steroids. Although a patch test with iopromide was negative in our case, we made a diagnosis of FDE due to iopromide because the skin lesions occurred again at the previously involved area after re-exposure to iopromide. To date, only three cases of FDE caused by non-ionic monomers have been documented in the English literature. Herein, we report on an interesting case of FDE caused by iopromide.

Monitoring non-immediate allergic reactions to iodine contrast media

Non-immediate reactions to iodine contrast media (ICM) affect 2-5% of patients receiving these agents. We studied the immunological mechanisms involved in patients with a confirmed non-immediate reaction, maculopapular exanthema, after administration of ICM. The diagnosis was carried out by skin testing or drug provocation test. The immunological study was performed in sequential peripheral blood mononuclear cells taken from the onset of the reaction by flow cytometry and in skin biopsy by immunohistochemistry, with specific recognition by the lymphocyte transformation test (LTT) with different ICM. Flow cytometry showed an increase in the different activation markers [CD69, CD25 and human leucocyte antigen D-related (HLA-DR)] and the skin homing receptor [cutaneous lymphocyte-associated antigen (CLA)] in CD4 lymphocytes, whereas perforin was higher in the CD8 lymphocytes. The skin biopsy showed a perivascular mononuclear infiltrate composed of CD4 lymphocytes, expressing CD25, HLA-DR and CLA, with eosinophils. Intradermal skin tests and the LTT were positive to several ICM, including the culprit agent in four and three patients, respectively, with negative results in all 10 tolerant controls. We showed that a specific immunological mechanism was implicated in patients with non-immediate reactions to ICM. Moreover, the positive results in skin tests and lymphocyte proliferation tests indicated that an important cross-reactivity exists.

Fixed drug eruption induced by an iodinated non-ionic X-ray contrast medium: a practical approach to identify the causative agent and to prevent its recurrence

We describe the case of a 61-year-old physician who developed a fixed drug eruption (FDE) after i.v. administration of a non-ionic monomeric iodinated X-ray contrast medium (CM) (iopromide). During CM injection, a sensation of heat occurred, which was most intense in the right inguinal region. Four hours later, the FDE arose with a red macule of approximately 2 cm in diameter covering a dermal infiltration in the right inguinal region, and enlarged up to a final size of 15 x 8 cm, accompanied by a burning sensation. The patient's history revealed a similar reaction in the same localization and of the same clinical appearance after CM injection 1 year before. Patch testing 4 months later revealed positive reactions to iomeprol and iohexol. Iopamidol injection for another CT examination 23 months later was well tolerated. Based on these results, we suggest patch testing after CM-induced FDE, which could help to select a CM for future CT examinations. Late onset of adverse CM reactions may manifest as FDE. Patch testing within the previous skin reaction area is the diagnostic tool that should be used to confirm the suspected agent, possible cross-reacting agents and well-tolerated agents.

Possible role of Fas/Fas ligand-mediated apoptosis in the pathogenesis of fixed drug eruption

BACKGROUND

Although epidermal and dermal T cells play roles in the pathogenesis of fixed drug eruption (FDE), not much is known about keratinocyte death and its precise mechanism in FDE.

OBJECTIVES

Our aim is to elucidate the mechanism that underlies keratinocyte death in FDE, that is, the role of apoptosis and its signalling pathway.

METHODS

We first examined the involvement of apoptosis in the active FDE lesions by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labelling (TUNEL) assay and immunohistochemical analysis of caspase-3. We then examined the expressions of Fas and Fas ligand (FasL) to deduce the possible upstream signalling pathway of apoptosis, if apoptosis were involved. We finally characterized the infiltrated T-cell subpopulations in the active FDE lesions.

RESULTS

In the active FDE lesions, TUNEL positivity was strongly observed in the basal keratinocytes, and also weakly observed in the upper dermal infiltrates as well as in a few keratinocytes in the granular layer. The distribution of TUNEL-positive cells was similar to that of the strong staining of active capase-3. Fas was found mainly in the keratinocytes and some infiltrated dermal cells, whereas FasL was identified predominantly in the intraepidermal and dermal infiltrated cells and in some basal keratinocytes. Overlapping expression of Fas and FasL was accompanied by apoptosis in the FDE lesions. Many of the infiltrated mononuclear cells were CD8+. Perforin was rarely observed in the FDE lesions.

CONCLUSIONS

These findings suggest that apoptosis of the keratinocyte is highly likely to be involved in the pathogenesis of FDE, and this cytotoxicity might be predominantly mediated by the FasL of the infiltrating CD8+ T cells, possibly also playing an inflammatory role.

A practical guide to diagnose lesser-known immediate and delayed contrast media-induced adverse cutaneous reactions

The terms "immediate" and "delayed" adverse reactions induced by contrast media (CM) refer to the reactions' onset but do not provide substantial information concerning the clinical manifestation, the potential risk factors, the treatment modalities, or prevention. Because a variety of different reactions caused by different pathophysiological mechanisms may arise immediately or be delayed after CM injection, and because these need different management, the aim of the present paper is to present the clinical features and to exactly characterize lesser-known cutaneous reactions. A thorough knowledge of the clinical features, their adequate treatment, and, possibly, the subsequent diagnostic procedure for preventing recurrence after reexposure to CM would improve patient management.

Low negative predictive value of skin tests in investigating delayed reactions to radio-contrast media

Delayed reactions to radio-contrast media (RCM) with positive skin tests are rare. We report the study of a series of 15 patients who presented delayed reactions to RCM, with an analysis of the clinical features and the results of standardized drug skin tests. Patch tests were performed with RCM and iodized antiseptics (IAs). If negative, prick tests were performed, followed by intradermal tests (IDTs), then intravenous administration under hospital surveillance. The main clinical features were maculopapular rashes or a macular rubella-like rashes. Patch tests were positive with RCM in 2 of 15 cases and with IAs in 4 of 15 cases. All the prick tests were negative. IDTs were positive at 24 h in 8 of 15 cases. 5 of 12 patients had a non-severe relapse of the rash upon receiving an RCM despite clearly negative skin tests with the readministered RCM. Visipaque cross-reacted with Iopamiron, Iomeron, Telebrix, Omnipaque, Xenetix and Hexabrix. Omnipaque cross-reacted with Hexabrix and Iopamiron. IDTs with delayed readings are of better value than patch tests in such patients. The readministration of RCM with negative IDTs must be performed with progressive amounts under hospital surveillance. Cross-reactions between various classes of RCM are frequent. The responsible epitopes are unknown. Iodine itself could be involved.

Enhanced expression of p16 in seborrhoeic keratosis; a lesion of accumulated senescent epidermal cells in G1 arrest

BACKGROUND

Seborrhoeic keratosis (SK) is a common skin disease associated with skin ageing and photoageing, but only limited studies have been performed on SK and the senescence of keratinocytes.

OBJECTIVES

We sought to clarify the genetic basis of SK and the senescence of keratinocytes.

METHODS

Expression of p16, cyclins A, D and E, p21, p53, retinoblastoma (Rb) gene product and telomerase-associated protein 1 (TP1) in SK was examined by immunohistochemistry. DNA fragmentation in SK was detected by the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labelling method. We cultured keratinocytes from SK lesions and non-lesional epidermis and examined expression of p16, observed morphology of the cultured cells by light and electron microscopy and measured survival time.

RESULTS

p16, a cyclin-dependent kinase inhibitor, was expressed in all cells from SK lesions, whereas normal keratinocytes expressed p16 only in the granular cells. Other factors such as cyclins A, D and E, p21, p53, Rb gene product, and TP1, were not expressed in SK cells. These results suggest that p16 expression is a marker of SK and that p16 has a role in the pathogenesis of SK. DNA fragmentation was not detected in four of five SK tissue samples; one of the SK tissue samples showed DNA fragmentation only in the superficial upper layer of an SK lesion, suggesting that apoptosis was inhibited in SK cells. In contrast, normal epidermis showed DNA fragmentation in the granular and squamous layers. Immunohistochemical examination of cultured SK cells also revealed the presence of p16. A greater number of SK cells survived after 3 weeks of culture in comparison with normal keratinocytes. Features of senescence, such as a balloon-like appearance after lengthy culture and increased amounts of tonofilaments in cytoplasm, were observed in SK cells in culture.

CONCLUSIONS

These results suggest that SK is a benign neoplasm where keratinocytes in a senescent condition and G1 arrest are accumulated.

Effective prophylactic protocol in delayed hypersensitivity to contrast media: report of a case involving lymphocyte transformation studies with different compounds

A patient with maculopapular reactions to iopamidol needed to undergo angiography for a cerebral arteriovenous malformation. In vivo and in vitro tests were performed with ionic and nonionic contrast media, including iopamidol and iobitridol. All results were positive, demonstrating delayed hypersensitivity. The patient received 6-alpha-methylprednisolone and cyclosporine 1 week before and 2 weeks after four angiograms were obtained with the use of iobitridol, which was well tolerated.

Late-onset allergy-like reactions to X-ray contrast media

PURPOSE OF REVIEW

The purpose of the present review is to describe recent insight into the pathomechanism of the late-onset allergy-like reactions which affect 2-3% of contrast medium-exposed patients, and to give advice regarding prophylactic measures to avoid recurrence of such reactions.

RECENT FINDINGS

It is well recognized that the majority of contrast media-induced late-onset reactions are cutaneous reactions of the maculopapular, urticarial and angioedema types, with occasional occurrence of more serious, bullous eruptions. Recent findings strongly indicate that these reactions are T cell-mediated. The current evidences for this concept are the described clinical symptoms; the high incidence of reactions in interleukin-2-treated patients; the positive results from skin, provocation and lymphocyte transformation testing of affected patients; and the histopathology of skin eruptions and positive skin test sites.

SUMMARY

On the basis of this new knowledge, several prophylactic measures are proposed to avoid repeat reactions in patients with previous late-onset contrast medium reactions. All persons receiving contrast media should be informed that transient skin reactions may develop up to 7 days after contrast medium exposure. Those who experience such reactions should be advised to see an allergist for diagnosis of the reaction. Skin testing with a panel of different contrast media appears to be useful for confirming the presence of an allergic reaction and for identifying alternative contrast media that can be safely used. For undiagnosed persons, a contrast medium that is structurally different from the product that precipitated the reaction should be chosen if re-exposure to contrast media is required. Pretreatment with corticosteroids may also be tried, although its protective effect has not been systematically studied.

Fixed drug eruptions. Incidence, recognition, and avoidance

Drug eruptions often have nonspecific clinical findings, and the evaluation of the probability of an eruption being a drug-induced event is difficult. A few types of drug eruption do not present such problems, and the fixed drug eruption is one of those whose clinical findings are specific enough to allow a diagnosis. The fixed drug eruption is a commonly reported type of drug eruption. The incidence of fixed drug eruptions has tended to increase, although the overall number of drug eruption cases has decreased. This is one of the reasons why fixed drug eruptions are familiar to dermatologists. The most characteristic findings of a fixed drug eruption are recurrence of similar lesions at the same sites and healing with residual hyperpigmentation. The residual hyperpigmentation serves as an indicator of site recognition. Diagnosis is not always easy; for example, as is the case for nonpigmenting fixed drug eruptions, which do not have any residual hyperpigmentation. The development of molecular biology may help to clarify the pathogenesis of fixed drug eruptions, but the reason for their recurrence on the same sites is still unknown. Identification of the causative drug or drugs is essential for the management of fixed drug eruptions, as it is for other drug eruptions. The causative drug or drugs and cross-reactants should be avoided to prevent recurrence. To date, rechallenge is the most reliable method of identifying causative drugs, but increasingly the use of skin tests has gained the attention of investigators. The validity and the problems of skin tests are discussed, and an approach to the clinical management of fixed drug eruptions is presented.

Delayed-type hypersensitivity to a nonionic, radiopaque contrast medium

BACKGROUND

True allergic reactions to iodinated radiocontrast media are rare, and only a few well-documented cases of delayed-type hypersensitivity reactions caused by contrast media have been described.

METHODS

We report a 61-year-old patient in whom percutaneous transluminal coronary angioplasty (PTCA) was performed with iopamidol, a nonionic contrast medium. Seven days later, the patient developed generalized maculopapular exanthema. Repeated patch tests with several iodinated agents were performed.

RESULTS

A first patch test with iopamidol was positive. Repetition of the patch tests showed positive results to iopamidol as well as to iohexol and ioversol, two other nonionic contrast media, but not to other iodinated substances. Three months later, PTCA was repeated, and iopamidol was used again. Despite premedication, pruritic macular exanthema developed 1 day later. Whether iopamidol or trometamol -- an additive substance in the contrast medium -- was causative could not be determined, since a third set of patch tests was negative.

CONCLUSIONS

Delayed-type hypersensitivity reactions to iodinated contrast media are rare. We recommend that patients with delayed exanthematous reactions undergo patch or intradermal tests with different contrast media and their additives, and that readings be performed immediately and later at days 2 and 3.