Primary cutaneous follicular helper T-cell lymphoma: diagnostic pitfalls of this new lymphoma subtype.

The recently proposed entity of cutaneous follicular helper T (T(FH)) cell lymphoma (CT(FH)CL) harbors distinct clinical and histopathologic features. Here, diagnostic pitfalls are exemplified in a case report and by review of the literature. A 45-year-old patient developed rapidly growing nodules and plaques on upper arms and buttocks, which were initially misdiagnosed as primary cutaneous follicle center B-cell lymphoma (CFCL). Consequently, systemic therapy with rituximab failed and consecutive skin biopsies revealed CT(FH)CL (CD3+CD4+CD10+PD-1+bcl6+ICOS+CXCL13+). Interestingly, the prima vista PD-1-positive and CD10-positive tumor cells lost PD-1 expression in follow-up biopsies while retaining CD10, ICOS and CXCL13 expression. All biopsy specimens displayed an identical clonal T-cell population. Initially, nodules were controlled by local radiotherapy and oral psoralen combined with ultraviolet A (PUVA) therapy. However, disease recurred and progressed rapidly with disseminated nodules. Treatment with bexarotene, methotrexate and polychemotherapy failed to stop disease progression. Finally, modified total skin electron beam radiation resulted in complete remission. Disease stabilized on maintenance therapy with bexarotene in combination with ultraviolet A (UVA) therapy. The case highlights that because of concomitant B-cell stimulation, CT(FH)CL clinicopathologically is prone to be mistaken for CFCL. Importantly, CT(FH)CL might lose PD-1 while retaining CD10 expression in later stages, which may lead to confusion in distinguishing CT(FH)CL from CFCL.

Do-it-yourself cement work: the main cause of severe irritant contact dermatitis requiring hospitalization.

BACKGROUND: There are myriads of potentially irritant agents causing acute irritant contact dermatitis. In the large majority of cases, dermatitis is mild to moderate, and patients do not need hospitalization. However, some agents or special circumstances may cause severe dermatitis requiring more intensive therapy. OBJECTIVES: The aim of this study was to evaluate causative agents of severe acute irritant contact dermatitis requiring hospitalization. METHODS: In this single-centre observational cohort study, we included 54 consecutive patients presenting with signs and symptoms of acute irritant contact dermatitis for which hospitalization was necessary. The severity of dermatitis was graded (grade I-IV) according to intensity, and details related to the skin irritation (irritant agent, area of exposure, time interval to onset of symptoms, and duration of hospitalization) were determined. RESULTS: All cases with severe ulcerative dermatitis (grade IV) were caused by wet cement, owing to prolonged skin contact. These cement burns are clearly associated with amateur work, younger age, male preponderance, and leg localization. CONCLUSIONS: The study data provide clear-cut evidence that wet cement is a severely irritant substance that regularly causes the most severe form of acute irritant contact dermatitis. The main causative prerequisite for these cement burns is do-it-yourself work with poor protective measures.

An intact retinoblastoma protein-binding site in Merkel cell polyomavirus large T antigen is required for promoting growth of Merkel cell carcinoma cells.

Merkel cell carcinoma (MCC) is a highly aggressive skin cancer that frequently harbours Merkel cell polyomavirus (MCV) DNA integrated in the genome of the tumor cells. In our study, we elaborate our recent finding that MCV-positive MCC cell lines require the expression of the viral T antigens (TA). Indeed, in a xeno-transplantation model, we prove that TA expression is essential also in an in vivo situation, as knock down of TA leads to tumor regression. Moreover, rescuing TA short hairpin RNA (shRNA)-treated MCV-positive MCC cells by ectopic expression of shRNA-insensitive TAs clearly demonstrates that the observed effect is caused by TA knockdown. Notably, introduction of a mutation in the LTA protein interfering with LTA binding to the retinoblastoma protein (RB) ablated this rescue. The importance of this interaction was further confirmed as LTA-specific knockdown leads to explicit cell growth inhibition. In summary, the presented data demonstrate that established MCV-positive MCC tumors critically depend on TA expression, in particular the LTA and RB interaction, for sustained tumor growth. Consequently, interference with LTA/RB interaction appears as promising strategy to treat MCC.

Survivin-specific T-cell reactivity correlates with tumor response and patient survival: a phase-II peptide vaccination trial in metastatic melanoma.

BACKGROUND: Therapeutic vaccination directed to induce an anti-tumoral T-cell response is a field of extensive investigation in the treatment of melanoma. However, many vaccination trials in melanoma failed to demonstrate a correlation between the vaccine-specific immune response and therapy outcome. This has been mainly attributed to immune escape by antigen loss, rendering us in the need of new vaccination targets. PATIENTS AND METHODS: This phase-II trial investigated a peptide vaccination against survivin, an oncogenic inhibitor-of-apoptosis protein crucial for the survival of tumor cells, in HLA-A1/-A2/-B35-positive patients with treatment-refractory stage-IV metastatic melanoma. The study endpoints were survivin-specific T-cell reactivity (SSTR), safety, response, and survival (OS). RESULTS: Sixty-one patients (ITT) received vaccination therapy using three different regimens. 55 patients (PP) were evaluable for response and survival, and 41/55 for SSTR. Patients achieving progression arrest (CR + PR + SD) more often showed SSTRs than patients with disease progression (p = 0.0008). Patients presenting SSTRs revealed a prolonged OS (median 19.6 vs. 8.6 months; p = 0.0077); multivariate analysis demonstrated SSTR as an independent predictor of survival (p = 0.013). The induction of SSTRs was associated with gender (female vs. male; p = 0.014) and disease stage (M1a/b vs. M1c; p = 0.010), but not with patient age, HLA type, performance status, or vaccination regimen. CONCLUSION: Survivin-specific T-cell reactivities strongly correlate with tumor response and patient survival, indicating that vaccination with survivin-derived peptides is a promising treatment strategy in melanoma.

Hazard rates for recurrent and secondary cutaneous melanoma: an analysis of 33,384 patients in the German Central Malignant Melanoma Registry.

BACKGROUND: Knowledge about the risk for recurrence and secondary cutaneous melanoma (CM) is an important basis for patient counseling and planning of follow-up examinations. OBJECTIVES: This study aimed to analyze stage- and time-dependent hazard rates (HR) and discusses current surveillance recommendations. METHODS: Follow-up data of 33,384 patients with incident CM in stages I to III (American Joint Committee on Cancer 2002) were recorded by the German Central Malignant Melanoma Registry in 1976 through 2007. Survival was based on Kaplan-Meier estimates and HRs were calculated. RESULTS: Recurrences were recorded in 4999 patients (stage I, 7.1%; stage II, 32.8%; and stage III, 51.0%). Ten-year recurrence-free survival was 78.9% (95% confidence interval 73.1-90.5); in stage I, 89.0%; stage II, 56.9%; and stage III, 36.0%. Whereas HR for recurrent CM showed a constantly low level less than or equal to 1:125 per year for stage IA, clearly higher HRs of greater than or equal to 1:40 were recorded in stage IB for the first 3 years and generally in stages II to III. Of all patients 2.3% developed secondary melanomas, with a consistently low HR of less than 1:220 per year. LIMITATIONS: As German recommendations discontinued regular follow-up examinations after 10 years, no information can be given beyond this time point. Follow-up data of longer than 5 years were available in 41.4% of patients. CONCLUSION: For patients at stage IA with thin melanoma and low HR for recurrent CM the need for surveillance remains questionable. For patients with higher HR greater than 1:40 per year, intensified surveillance strategies should be taken into account.

Wasp venom immunotherapy induces activation and homing of CD4(+)CD25(+) forkhead box protein 3-positive regulatory T cells controlling T(H)1 responses.

BACKGROUND: Despite a growing interest in CD4(+)CD25(+) forkhead box protein 3 (Foxp3)-positive regulatory T (Treg) cells, the fundamental parameters of the activation and homing of these cells during wasp venom immunotherapy (VIT) are largely unknown. OBJECTIVE: We investigated longitudinally the phenotype and function of Treg cells in a well-characterized homogeneous group of patients with wasp venom allergy during VIT. METHODS: In 30 patients peripheral Treg cells were ex vivo monitored for their activation status and homing capacities by means of flow cytometric analysis before and after 1 and 6 months of VIT. In addition, the in vitro suppressive activity of Treg cells, as well as cytokine secretion, in response to wasp venom was analyzed. RESULTS: One month after initiating VIT, the proportion of both CD4(+)CD25(+)Foxp3(+) and CD4(+)Foxp3(+) Treg cells significantly decreased in peripheral blood. Coexpression of the lymph node homing receptors CCR7/CD62L were induced in CD4(+)Foxp3(+)CD45RO(+) Treg cells, indicating recirculation of VIT-activated Treg cells in secondary lymphoid organs. In vivo imaging by means of color duplex ultrasonography of the axillary draining lymph nodes demonstrated a VIT-induced 4-fold augmentation in afferent arterial blood flow. Furthermore, increased activation markers (CD45RO and HLA-DR) of Treg cells correlated with effective in vitro suppression of wasp venom-driven T-cell proliferation. After 1 month of VIT, Treg cell depletion in vitro greatly enhanced wasp venom-induced IFN-γ secretion. CONCLUSIONS: Allergen exposure during VIT simultaneously induces the activation and selective homing of circulating Treg cells. Functionally, on the one hand, Treg cells balance the immune reaction toward tolerance, and on the other hand, they are involved in controlling overwhelming T(H)1 responses.

A dynamic immunological synapse mediates homeostatic TCR-dependent and -independent signaling.

For homeostasis, T cells integrate non-cognate TCR-dependent and -independent signals to survive and weakly proliferate. In contrast to antigen-specific, stable, and long-lived contacts, signaling in short-lived homeostatic interactions depends upon the coordination of ongoing T-cell migration on the surface of DC and signaling at the cell-cell junction. To mimic peripheral tissues and analyze how T-cell migration and cell-cell signaling are integrated, we used live-cell imaging and 3-D reconstruction of fixed conjugates between DO11.10 T cells and DC in 3-D low-density collagen matrices. T cells simultaneously maintained amoeboid migration and polarized towards the DC, leading to a fully dynamic interaction plane that delivered signals for homeostatic T-cell survival and proliferation. The contact plane comprised three zones, the actin-rich leading edge poor in signal but driving migration, a mid-zone mediating TCR/MHC-induced signal associated with proliferation, and the rear uropod mediating predominantly MHC-independent signals. Thus a dynamic immunological synapse with distinct signaling sectors enables moving T cells to serially sample resident tissue cells and acquire molecular information "en passant".

Diagnosis of drug hypersensitivity in children and adolescents: discrepancy between physician-based assessment and results of testing.

BACKGROUND: Diagnosis of drug hypersensitivity is often based on history alone. But such a vague diagnosis may cause limitations of therapeutic options in the future. To confirm or rule out drug hypersensitivity, skin testing, in vitro studies, and challenge tests are necessary. However, the diagnostic value of this complex and time-consuming allergologic work-up, especially in children, remains controversial. OBJECTIVE: Aim of this retrospective analysis was to compare the results of diagnostic testing in children and adolescents with drug hypersensitivity diagnosed on clinical grounds, i.e., temporal relationship and observation of symptoms alone. METHODS: We studied 43 children and adolescents (23 females, 20 males, mean age 13) with a history of immediate or delayed hypersensitivity symptoms in temporal relation to drug treatment using standardized skin testing followed by oral challenges. Patients with suspected penicillin hypersensitivity were further evaluated with in vitro tests. RESULTS: Drug hypersensitivity was excluded in 40 patients by tolerated oral challenge tests with the incriminated drug. In two patients, positive challenge tests confirmed non-steroidal anti-inflammatory drug hypersensitivity. One patient with amoxicillin-associated exanthema developed positive late skin test reactions to aminopenicillins. CONCLUSION: In childhood and adolescence, allergologic testing in cases of suspected drug hypersensitivity is of importance both to establish a correct diagnosis and to prevent unjustified withholding of a drug or class of drugs.

Suspicion of macrolide allergy after treatment of infectious diseases including Helicobacter pylori: results of allergological testing.

BACKGROUND: Macrolides are useful in a wide range of bacterial infections including upper and lower respiratory tract, skin, and sexually transmitted diseases and are used in Helicobacter pylori eradication regimen. Skin symptoms occurring during drug therapy are mostly attributed to the antibiotic, causing considerable limitations of future therapeutic options. The aim of this retrospective analysis was to demonstrate results of diagnostic testing in cases of clinically suspected immediate and delayed macrolide hypersensitivity. METHODS: A total of 125 patients with a history of immediate or delayed hypersensitivity symptoms in temporal relation to treatment with a macrolide antibiotic were studied using standardised skin tests followed by oral challenges. Selected patients with severe symptoms were further evaluated with in vitro tests. RESULTS: Macrolide hypersensitivity was excluded in 109 patients (87.2%) by tolerated oral challenge tests. During 113 challenges in four patients an exanthema was provoked by the suspected macrolide. Only one patient developed a positive late skin test reaction. Out of the 28 Helicobacter pylori-treated patients, one patient with clarithromycin allergy was identified, whereas in eight cases amoxicillin allergy caused the exanthema. Laboratory tests using the suspected macrolides were constantly negative. CONCLUSIONS: History alone leads to an over-estimation of macrolide hypersensitivity. Moreover, skin and in vitro tests seem to be not very useful in identifying hypersensitive patients. Challenge tests appear to be necessary for definitely confirming or ruling out macrolide allergy.

Leg ulceration in rheumatoid arthritis--an underreported multicausal complication with considerable morbidity: analysis of thirty-six patients and review of the literature.

BACKGROUND: Rheumatoid arthritis (RA) is a systemic inflammatory disease which may present with extra-articular symptoms, including cutaneous manifestations. Ulcerated rheumatoid nodules, necrotic vasculitic lesions and pyoderma gangrenosum are fairly characteristic and well-recognized causes of skin ulcers in RA. However, most RA patients develop leg ulcers due to other pathophysiological factors posing a diagnostic and therapeutic challenge and leading to considerable morbidity. METHODS: A retrospective chart analysis of all patients with RA and leg ulcers hospitalized at our Dermatology Department between January 1998 and March 2008 was performed to evaluate risk factors and identify underlying conditions that predispose RA patients to the development of leg ulcers. RESULTS: A total of 36 patients with RA and leg ulcers were identified. Three patients presented with necrotizing vasculitis and 2 with pyoderma gangrenosum. Chronic venous insufficiency was diagnosed as the underlying cause of leg ulcers in 8 patients, peripheral arterial disease in 4 patients, and combined arterial and venous malfunction in 3 patients. Five patients suffered from pressure ulcers. Interestingly, in 11 patients (31%) other underlying causes besides constricted mobility followed by secondary lymphedema could not be identified, and these ulcers were classified as 'inactivity leg ulcers'. CONCLUSIONS: The majority of leg ulcers in patients with RA are due to underlying venous/arterial malfunction while vasculitic or traumatic ulcers are less common. Additionally, we identified a relevant subgroup of patients with 'inactivity ulcers' due to impaired mobility and consecutive lymphedema. Morphology and localization of ulcerations as well as duplex sonography provide the most important clues for accurate diagnosis, ensuring adequate treatment.

Dermal schwannoma (neurilemmoma): a peculiar foreign body reaction?

Schwannoma is usually a subcutaneous benign neoplasm that derives from nerve sheath. Pain and neurologic symptoms are uncommon, and exclusively dermal tumors are very rare. Solitary schwannoma has a traumatic origin in some cases, and rarely occur as a part of neurofibromatosis or schwannomatosis. An association of deeply located schwannoma with foreign material has been reported in very few cases. To our knowledge, we present the first case of a painful dermal schwannoma in association to foreign material.

Allergy diagnostic testing in clindamycin-induced skin reactions.

BACKGROUND: In clinical practice, clindamycin is increasingly used because of its good tolerability and high efficacy with excellent tissue penetration. However, with increased application of clindamycin, the frequency of side effects such as skin eruptions rises and the need for diagnostic testing to identify clindamycin allergy increases. The aim of this retrospective analysis was to demonstrate the results of skin and challenge tests in cases of clinically suspected clindamycin allergy. METHODS: We evaluated 33 patients with a history of a skin reaction in temporal relation to treatment with clindamycin using standardized patch and prick skin testing. In the case of negative skin tests, oral challenges were performed. RESULTS: Clindamycin hypersensitivity was excluded in 20 patients by negative skin tests and subsequently tolerated oral challenge tests. In 5 patients, positive skin tests strongly suggested delayed-type non-IgE-mediated allergic clindamycin hypersensitivity. In 6 skin test-negative patients (2 patients refused challenge tests), a rash was provoked by controlled challenge tests. CONCLUSIONS: The evaluation of patients with clindamycin-associated skin reactions should include appropriate allergologic tests establishing or excluding the diagnosis of clindamycin hypersensitivity. Combined testing, i.e. skin tests and subsequent challenge tests, appears to be necessary to definitely confirm or rule out the presence of allergic clindamycin hypersensitivity.

Compensation mechanism in tumor cell migration: mesenchymal-amoeboid transition after blocking of pericellular proteolysis.

Invasive tumor dissemination in vitro and in vivo involves the proteolytic degradation of ECM barriers. This process, however, is only incompletely attenuated by protease inhibitor-based treatment, suggesting the existence of migratory compensation strategies. In three-dimensional collagen matrices, spindle-shaped proteolytically potent HT-1080 fibrosarcoma and MDA-MB-231 carcinoma cells exhibited a constitutive mesenchymal-type movement including the coclustering of beta 1 integrins and MT1-matrix metalloproteinase (MMP) at fiber bindings sites and the generation of tube-like proteolytic degradation tracks. Near-total inhibition of MMPs, serine proteases, cathepsins, and other proteases, however, induced a conversion toward spherical morphology at near undiminished migration rates. Sustained protease-independent migration resulted from a flexible amoeba-like shape change, i.e., propulsive squeezing through preexisting matrix gaps and formation of constriction rings in the absence of matrix degradation, concomitant loss of clustered beta 1 integrins and MT1-MMP from fiber binding sites, and a diffuse cortical distribution of the actin cytoskeleton. Acquisition of protease-independent amoeboid dissemination was confirmed for HT-1080 cells injected into the mouse dermis monitored by intravital multiphoton microscopy. In conclusion, the transition from proteolytic mesenchymal toward nonproteolytic amoeboid movement highlights a supramolecular plasticity mechanism in cell migration and further represents a putative escape mechanism in tumor cell dissemination after abrogation of pericellular proteolysis.

Anetodermic pilomatricoma.

A pilomatricoma, or Malherbe's calcifying epithelioma, is an uncommon tumor originating from hair matrix cells. It is clinically characterized by a solitary, firm nodule. As the skin overlying the pilomatricoma may change in color and texture, its clinical presentation can vary. We report an unusual case of pilomatricoma with associated anetoderma on the lower extremity of a 12-year-old girl. Histology revealed a thinned dermis replaced by myxomatous tissue between the surface and a deep-seated tumoral mass. This mass is formed of irregular islands of basaloid cells, shadow cells, calcified areas and discrete inflammatory and foreign-body reactions surrounding it. Anetodermic cutaneous changes may occur in pilomatricomas without histological evidence of triggering factors.

Multiple pilomatricomas and gliomatosis cerebri--a new association?

Pilomatricomas are benign skin tumors originating from hair follicle matrix cells. In 2% to 3.5% of cases they occur in multiplicity and then may be associated with genetic diseases, such as myotonic dystrophy Curschmann-Steinert, familial adenomatous polyposis (Gardner syndrome), and Rubinstein-Taybi syndrome. A 15-year-old boy treated with temozolomide and oxcarbazepine for gliomatosis cerebri with symptomatic epilepsy developed four firm cutaneous nodules on his face and right upper arm in the course of 1 year. All four tumors were excised under local anesthesia. Histological examination confirmed the clinical diagnosis of pilomatricomas. This is the first published case of a patient suffering from gliomatosis cerebri and developing multiple pilomatricomas. Whether this observation represents a new association or is a mere coincidence cannot be clarified at present.

Prospective analysis of the incidence of autoimmune bullous disorders in Lower Franconia, Germany.

BACKGROUND: Only limited epidemiologic data are available on autoimmune bullous diseases. Improved diagnostic tools should have led to an increased incidence. To test this hypothesis, all patients with autoimmune bullous disorders who were treated in the Department of Dermatology at the University of Würzburg, Germany, between January 2001 and June 2002 were analysed prospectively. PATIENTS AND METHODS: Epidemiologic data of patients diagnosed with an autoimmune bullous disease during this time period were registered and statistically evaluated. Diagnosis was based on the clinical picture and specific immunopathological findings. Only patients from Lower Franconia, a well-defined administrative region of Southern Germany, were included into this study. RESULTS: During the study period, 41 patients with an autoimmune bullous disease were diagnosed, including 27 with bullous pemphigoid, 4 with pemphigoid gestationis and mucous membrane pemphigoid, 2 with dermatitis herpetiformis and linear IgA disease, and 1 with epidermolysis bullosa acquisita and pemphigus vulgaris, respectively. The highest incidence was calculated for bullous pemphigoid (13.4 per 1 million inhabitants per year) followed by pemphigoid gestationis (2.0) and mucous membrane pemphigoid (2.0). Patients with mucous membrane pemphigoid were found to have the highest mean age at disease onset (76 years) followed by patients with bullous pemphigoid (74 years). CONCLUSIONS: This is the first prospective study on the incidence of autoimmune bullous disorders. Subepidermal blistering autoimmune diseases were shown to be more frequent than previously reported for Central Europe. This is most likely due to improved diagnostic tools for and increased awareness of these diseases.

Therapy of metastasized Merkel cell carcinoma with liposomal doxorubicin in combination with radiotherapy.

BACKGROUND: Merkel cell carcinoma is a rare skin cancer of neuroendocrine origin, which is characterized by a high rate of recurrence, metastatic spread and mortality. Because of its rarity, evidence-based therapeutic regimens are difficult to establish. Merkel cell carcinoma is known to be both radio- and chemosensitive. Toxicity is a key factor in assessing any regimen, as the patients are usually elderly and likely to have other significant medical problems. PATIENTS AND METHODS: We retrospectively evaluated five patients with metastatic Merkel cell carcinoma to see if liposomal doxorubicin (Caelyx) or Myocet) in combination with radiotherapy exhibited clinical anti-tumoral effects accompanied by acceptable side effects. RESULTS: The outpatient chemotherapy regimen was tolerated without major side effects and produced good response rates. All patients achieved at least tumor stabilization; four of five had a partial remission. Effects of therapy were usually seen in the first cycle of therapy but the responses were of short duration with an average interval of two months until progression. CONCLUSIONS: As combined radiochemotherapy with liposomal doxorubicin is well tolerated even in older patients with other illnesses and can be given on an outpatient basis, it is an attractive option for metastatic Merkel cell carcinoma. Based on response rate or overall survival, it offers no advantages compared to polychemotherapy.

Cutaneous metastases as the first clinical sign of metastatic gastric carcinoma.

Cutaneous metastases from gastric cancer are uncommon with a frequency of 7 % but can rarely be the presenting sign. A 54-year-old man complained of multiple pea-sized scalp nodules which had been present for four months. Histology showed a metastatic adenocarcinoma. Initial evaluation revealed liver metastases and gastroscopy then identified a tumor involving the distal esophagus and gastric cardia that was diagnosed as a gastric tubular carcinoma. The patient had a good response to polychemotherapy. While gastric carcinoma generally metastasizes to the abdominal wall or lymph nodes, our patient showed an exceptional variant with distant cutaneous metastases as the first clinical sign.

Anaphylaxis to iodinated contrast material: nonallergic hypersensitivity or IgE-mediated allergy?

OBJECTIVE: Contrast material is generally well tolerated although approximately 1% of patients who receive low-osmolar nonionic contrast material will develop anaphylaxis symptoms. Because most anaphylactic reactions are mild and nonallergic, clinically mimicking immunoglobulin E (IgE)-mediated allergy, diagnostic skin testing has been discussed controversially in the past and prophylactic pretreatment drug regimens are recommended instead. In the past 6 years, all patients with contrast material-induced anaphylaxis have been subjected to allergologic diagnostic procedures to clearly differentiate allergic and nonallergic anaphylaxis. Thus the purpose of our study was to identify and differentiate IgE-mediated allergy and nonallergic contrast material-induced hypersensitivity. Furthermore, the objective of our diagnostic procedures was not only to identify the culprit contrast material but also to find alternative contrast material for future radiologic interventions. SUBJECTS AND METHODS: We evaluated 96 patients with anaphylaxis symptoms after contrast material application using standardized intradermal skin testing. In patients with positive skin tests, the IgE-mediated allergy was further evaluated with in vitro and challenge tests. RESULTS: In four patients (suffering from anaphylaxis grades 2 and 3) out of the 96 (4.2%), skin tests and basophil activation tests strongly suggested IgE-mediated allergy to the contrast materials iopromide (two patients), iomeprol, and iopentol. In two patients with allergies to iopromide and iomeprol, alternative nonionic monomer contrast materials were tolerated, as identified in controlled challenge tests with iopamidol and iopromide, respectively. CONCLUSION: The evaluation of patients with contrast material-induced anaphylaxis (at least those with anaphylaxis > or = grade 2) should always include appropriate skin tests ensuring that patients with an IgE-mediated allergy are not missed. Moreover, allergologic testing may identify a contrast material of the group of nonionic monomers that will be tolerated in future radiologic interventions.