[PMC free article] [PubMed] [Google Scholar] 2. with topical Betamethasone dipropionate 0.05% ointment. Fourteen months into Pembrolizumab treatment, a second skin eruption with widespread pruritus and excoriated papules on limbs and torso (Figure ?(Figure3)3) presented and biopsy confirmed bullous pemphigoid with subepidermal vesicles and eosinophils. Immunofluorescence demonstrated IgG and C3c at the dermo\epidermal junction. Oral prednisolone induced remission, enabling continuation of Pembrolizumab. Open in a separate window Figure 1 Red/brown fixed, indurated, and tender papules and plaques Open in a separate window LOXO-101 (ARRY-470, Larotrectinib) Figure 2 H&E stain at magnification of punch biopsy showing well\formed, non\necrotizing granulomas and histiocytes Open in a separate window Figure 3 Excoriated papules on torso PD\1 inhibitors are a mainstay of metastatic melanoma treatment due to its efficacy,1 yet are implicated in multi\system autoimmune inflammatory adverse events. They cause a LOXO-101 (ARRY-470, Larotrectinib) LOXO-101 (ARRY-470, Larotrectinib) release from normal immune inhibition, analogous to releasing the brake on immune tolerance.2 Adverse dermatological events such as LOXO-101 (ARRY-470, Larotrectinib) lichen planus, lichenoid drug eruptions, dermatitis, bullous pemphigoid, acute localized exanthematous Mouse monoclonal to Neuropilin and tolloid-like protein 1 pustulosis, and Stevens\Johnson syndrome/ Toxic epidermal necrolysis have been reported.1, 3 Some events have even been suggested as positive prognostic factors, with improvements in melanoma patient survival with Pembrolizumab.1 Granulomatous reactions in the form of extensive panniculitis and granulomatous inflammation reactivation affecting the lungs in metastatic melanoma patients undergoing Pembrolizumab therapy have been described.4, 5 Cases of bullous pemphigoid associated with Pembrolizumab have also been reported, many with prior treatment with Ipilimumab.5 In our case, we describe an individual presenting with granulomatous panniculitis as well as bullous pemphigoid associated with pembrolizumab therapy. Our report appears to be the only recorded case showing multiple cutaneous immune\related adverse events in the same patient, expanding the clinical spectrum of cutaneous manifestations of Pembrolizumab therapy to include possibility of granulomatous panniculitis and polymorphic cutaneous autoimmune conditions in a single patient. As the use of PD\1 LOXO-101 (ARRY-470, Larotrectinib) inhibitors grows, clinicians must be cognizant of potential for associated immune\mediated cutaneous adverse effects. Here we aim to increase awareness of atypical presentations of Pembrolizumab therapy to facilitate earlier identification of the wide\ranging cutaneous side effects associated with immunotherapy. CONFLICT OF INTEREST No author has any conflicts of interest or relevant financial activities to disclose. AUTHOR CONTRIBUTION AH: first author and is a corresponding author. FL: involved in clinical care of patient and assisted in drafting the manuscript. JE: assisted in drafting the manuscript. OP: consultant?pathologist?involved in clinical care of patient and? assisted in drafting the manuscript. MG and CM: consultants involved in clinical care of patient and assisted in drafting the manuscript. Notes Honigman AD, Lai F, Elakis J, Prall O, Goh M, McCormack C. Pembrolizumab\induced sarcoid granulomatous panniculitis and bullous pemphigoid in a single patient. Clin Case Rep. 2019;7:773C775. 10.1002/ccr3.2090 [PMC free article] [PubMed] [CrossRef] [Google Scholar] REFERENCES 1. Sanlorenzo M, Vujic I, Daud A, et al. Pembrolizumab cutaneous adverse events and their association with disease progression. JAMA Dermatology. 2015;151(11):1206\1212. [PMC free article] [PubMed] [Google Scholar] 2. Okazaki T, Wang J. PD\1/PD\L pathway and autoimmunity. Autoimmunity. 2005;38(5):353\357. [PubMed] [Google Scholar] 3. Sibaud V. Dermatologic reactions to immune checkpoint inhibitors: skin toxicities and immunotherapy. Am J Clin Dermatol. 2018;19:345\361. [PubMed] [Google Scholar] 4. Burillo\Martinez S, Morales\Raya C, Prieto\Barrios M, Rodriguez\Peralto J\L, Ortiz\Romero P\L. Pembrolizumab\induced extensive panniculitis and nevus regression: Two novel cutaneous manifestations of the post\immunotherapy granulomatous reactions spectrum. JAMA Dermatology. 2017;153(7):721\722. [PubMed] [Google Scholar] 5. Lopez AT, Khana T, Antonov N, Audrey\Bayan C, Geskin L. A review of bullous pemphigoid associated with PD\1 and PD\L1 inhibitors. Int J Dermatol. 2018;57:664\669. [PubMed] [Google Scholar].