Dermatology was consulted and determined that the appearance of the rash was most consistent with a lichenoid drug eruption, likely secondary to vedolizumab that was administered 1 week before the rash onset. Analysis of a skin biopsy revealed a dense dermal histiocytic and lymphocytic infiltrate in close approximation to blood vessels, confirmed by immunohistochemical staining for CD45, CD43, CD68, CD34, c-KIT, and myeloperoxidase (Figures 2A and 2B). Colloidal iron staining of the specimen revealed no mucin (Figure 2C).
Photographs courtesy of William Beuerlein, DO (Jacksonville, Florida) and Angela Niehaus, MD (WinstonSalem, North Carolina).
FIGURE 2. A, Histopathology of a punch biopsy revealed a dense dermal infiltrate of mostly chronic inflammatory cells (H&E, original magnification ×400). B, Histiocytes cuffed blood vessels on immunohistochemistry (CD68, original magnification ×400). C, There was an absence of mucin with colloidal iron stain (original magnification ×4).
Taken together, the clinical presentation and histopathologic findings were determined to be most consistent with RGD, IGD type, with secondary vasculitis due to vedolizumab. The patient was treated with triamcinolone ointment and low-dose prednisone. Vedolizumab was discontinued. The rash resolved several weeks after cessation of vedolizumab.
Comment
This case describes the development of RGD, IGD type, as an AE of vedolizumab for the treatment of IBD. Reactive granulomatous dermatitis encompasses a spectrum of cutaneous reactions that includes the diagnosis formerly distinctly identified as IGD.11 This variety of RGD is characterized by histologic findings of heavy histiocytic inflammation in the reticular layer of the dermis with interstitial and perivascular neutrophils, lymphocytes, and histiocytes, as well as the absence of mucin. Interstitial granulomatous dermatitis–type reactions commonly are associated with autoimmune conditions and medications, with accumulating examples occurring in the setting of other biologic therapies, including the IL-6 receptor inhibitor tocilizumab; the programmed death receptor-1 inhibitor nivolumab; and the tumor necrosis factor α inhibitors infliximab, etanercept, and adalimumab.12-15
Although our patient represents CMV infection while being treated with vedolizumab, the relationship between the two is unclear. Development of CMV infection while receiving vedolizumab has been reported in the literature in a patient who was concurrently immunosuppressed with azathioprine.16 In contrast, vedolizumab administration has been utilized as a treatment of CMV infection in IBD patients, either alone or in combination with antiviral agents, with successful resolution of infection.17,18 Additional observations of the interaction between CMV infection and vedolizumab would be required to determine if the onset of CMV infection in this patient represents an additional risk of the medication.
Identifying a relationship between a monoclonal antibody therapy, such as vedolizumab, and RGD, IGD type, might be difficult in clinical practice, particularly if this type of reaction has not been previously associated with the culprit medication. In our patient, onset of cutaneous findings in relation to dosing of vedolizumab and exclusion of other possible causes of the rash supported the decision to stop vedolizumab. However, this decision often is challenging in patients with multiple concurrent medical conditions and those whose therapeutic options are limited.
Conclusion
Ulcerative colitis is not an uncommon condition; utilization of targeted monoclonal antibodies as a treatment strategy is expanding.2,19 As implementation of vedolizumab as a targeted biologic therapy for this disease increases, additional cases of IGD might emerge with greater frequency. Because IBD and autoimmune conditions have a tendency to coincide, awareness of the reaction presented here might be particularly important for dermatologists managing cutaneous manifestations of autoimmune conditions, as patients might present with a clinical picture complicated by preexisting skin findings.20 Furthermore, as reports of RGD, IGD type, in response to several monoclonal antibodies accumulate, it is prudent for all physicians to be aware of this potential complication of this class of medication so that they can make educated decisions about continuing monoclonal antibody therapy.