Effect of Immunosuppression on Patch Testing in Patients With IBD







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• The authors performed the first known randomized study to compare patch testing outcomes between immunocompetent and immunosuppressed patients, utilizing data from a 2009 study including 184 patients with inflammatory bowel disease. Of the 184 patients, 38 (20.7%) were on a systemic immunosuppressive agent during patch testing (6-mercaptopurine, prednisolone, infliximab, azathioprine, adalimumab, methotrexate, mycophenolate mofetil, or cyclosporine). Eighty-three patients with a total of 117 positive patch test results were identified: 13 patients on immunosuppressive therapy had at least 1 positive patch test result, and 70 of the immunocompetent patients had a positive patch test result (P = .130). There were no statistically significant differences between the groups in terms of age, gender, or reactivity to any tested allergens.

• Although the percentage of positive patch test results for patients in the immunosuppressed cohort was lower than in the immunocompetent cohort, there was no statistically significant difference between these two groups. The findings of this study suggest that patch testing can still be useful in patients on immunosuppressive therapies.

– Alex Noble, MD

Written by

 

 

Christen Maria MowadMD

Patch testing in those who are immunosuppressed, whether the immunosuppression be from systemic steroids, biologics, methotrexate, azathioprine or other immune modulators, has long been debated. The assumption is that these immunosuppressing drugs will result in false-negative patch-test results, although randomized, controlled studies have not been conducted. There have been reports published of positive patch-test reactions occurring in those who are on immunosuppressants, but there have not been controls to see if there was partial suppression or even complete suppression of other allergens or how the results would be different when someone is off immunosuppressants. This article is an interesting study, the dataset of which was initially collected to estimate the prevalence of steroid allergy in patients with inflammatory bowel disease. The authors then went back and evaluated the patients and compared differences in patch-test results between those on immunosuppressants and those not on immunosuppressants at the time of patch testing. They found that 34% of patients on immunosuppressants compared with 48% of those not on immunosuppressants had at least one positive patch-test result. This was not statistically significant. Patch testing in individuals on immunosuppressants remains an area of debate. As immunomodulators increase in usage the question of whether we can patch test these individuals remains. The data to date, although not from randomized controlled studies, indicate that patch testing can still be useful in those on immunosuppressants with the understanding that false negatives or some dulling of the reactions is possible. Lowering the dose or limiting immunosuppressants when possible is still ideal; but, when this is not feasible, patch testing will likely still provide some valuable information in those on immunosuppressants. Clinicians who suspect allergic contact dermatitis in those on immunosuppressants should still perform patch testing and explain the potential limitations to the patient.

Abstract 

Debate surrounds the validity of patch testing for allergic contact dermatitis in patients taking immunosuppressants and the extent to which these medications suppress patch test reactions. It is assumed that there is a significant risk of false‐negative results, although there are no randomized studies published which assess this. Several case series indicate that positive patch tests are seen in immunosuppressed patients1; however, the sensitivity in this situation has not been assessed. A retrospective review of 38 immunosuppressed patients demonstrated that positive patch tests can be elicited.2 A second retrospective review of 15 patients with psoriasis on biologics who were patch tested concluded that biologics do not appear to influence the abilities of patients to mount positive patch tests.3 Wentworth and David4 published a retrospective review of patients on immunosuppression who were patch tested to the standard series. They concluded that positive patch tests occur in patients on methotrexate, but how reactions would differ with no immunosuppression is unclear.

The Effect of Immunosuppression on Patch Testing: A Cross-Sectional Study in Patients With Inflammatory Bowel Disease

Contact Derm 2021 Jan 13;[EPub Ahead of Print], A Flynn, M Malik, S McCarthy, F Shanahan, J Bourke 

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Benjamin Hidalgo-Matlock
Skin Care Physicians of Costa Rica

Clinica Victoria en San Pedro: 4000-1054
Momentum Escazu: 2101-9574

Please excuse the shortness of this message, as it has been sent from
a mobile device.

Sent from my iPhone

Benjamin Hidalgo-Matlock
Skin Care Physicians of Costa Rica

Clinica Victoria en San Pedro: 4000-1054
Momentum Escazu: 2101-9574

Please excuse the shortness of this message, as it has been sent from
a mobile device.