Characteristics and Management of Immune Checkpoint Inhibitor–Induced Pruritus

Abstract 

BACKGROUND

Limited data on immune checkpoint inhibitor (ICI)-induced pruritus per se and efficacy of different therapeutic modalities in its management exist.

OBJECTIVE

To study the quantitative and qualitative characteristics of ICI-induced pruritus per se and to assess the efficacy of the therapeutic modalities usually applied.

METHODS

We retrospectively reviewed the records of 91 patients who were under treatment with ICIs for any kind of neoplasia and developed pruritus during treatment.

RESULTS

Twenty out of 91 individuals (22.0%) with ICI-induced pruritus had pruritus as the only symptom, while 71/91 (78.0%) presented with pruritus coexisting with an additional cutaneous toxicity. Pruritus was treated with antihistamines (18/20, 90.0%) and/or topical regimens, as first-line choice. In resistant cases, as a second therapeutic intervention, narrow-band UVB (NBUVB), oral steroids and GABA analogs were added (70.0%). Statistical analysis revealed a significant difference in mean pruritus Numerical Rating Scale (NRS) scores between baseline and sequential visits. Moreover, subgroup analysis revealed a significant reduction in mean NRS scores in those treated with phototherapy.

LIMITATIONS

Retrospective design, low number of patients and survivorship bias.

CONCLUSION

Pruritus per se was present in a substantial portion of our cohort (22.0%). Our study confirms the efficacy of current treatment strategies and suggests NBUVB as a potential steroid-sparing therapeutic alternative.

Photodermatology, Photoimmunology & Photomedicine

A retrospective multicentric cohort study of checkpoint inhibitors-induced pruritus with focus on management

Photodermatol Photoimmunol Photomed 2023 Jun 12;[EPub Ahead of Print], C Papageorgiou, E Lazaridou, K Lallas, K Papaioannou, V Nikolaou, V Mateeva, K Efthymiadis, C Koukoutzeli, K Loga, E Sogka, E Karamitrousis, G Lazaridis, D Dionysopoulos, A Lallas, C Kemanetzi, C Fotiadou, E Timotheadou, Z Apalla 

Written by

 

 

Angad A. Chadha MD

This limited retrospective cohort study evaluated the effect of a few treatment modalities in the management of immune checkpoint inhibitor–induced pruritus (ICI-pruritus). A total of 20 patients with pruritus as their only symptom from ICI therapy were studied. Patients received first-line and second-line therapies to address their pruritus. First-line therapy included oral antihistamines for all 20 patients, in addition to topical therapy in 18 of 20 patients. Of the 20 patients,  14 required second-line therapy, which included phototherapy in 7 patients, oral steroids in 2, further oral antihistamines in 2, a GABA-analogue in 1, and combination therapy in 2.

The average pruritus Numerical Rating Score (NRS) for all patients decreased from 6.0 to 4.1 after first-line therapy and then further from 4.1 to 1.6 after all second-line therapies regardless of treatment modality. Subgroup analysis revealed that the average NRS for the 7 patients treated with phototherapy decreased from 6.6 to 4.8 after first-line therapy, and then from 4.8 to 0.8 after second-line therapy with phototherapy. These results were similar in magnitude to those seen with systemic steroids, although only 2 patients were treated with systemic steroids compared with 7 patients with phototherapy.

This study provides some data in support of the use of the current expert consensus guidelines for the treatment of ICI-pruritus (PMID: 32856211) and adds some data in support of the use of phototherapy as a steroid-sparing agent in the treatment of ICI-pruritus. All dermatologists should consider the use of phototherapy for ICI-pruritus, given its steroid-sparing nature and favorable side-effect profile, especially in the oncology patient population, which is already burdened with medication side-effects.

This study was underpowered to discern differences in treatment response among the various second-line therapies listed above. The overall sample sizes for second-line therapies are very small and limit the external validity of this study. The authors did not provide dosages of phototherapy used, nor did they comment on how long into the phototherapy treatment course patients experienced improvement with their pruritus; the latter is of particular concern, given the time-sensitive nature of treating ICI-pruritus so that patients can stay on schedule with their ICI therapy.

NB: In Table 4 line 1, the authors report an NRS after second-line therapy for 20 patients; it is unclear where this number is derived from, as only 14 patients in this study actually receive second-line therapy.

TAKE-HOME MESSAGE

• This retrospective cohort study included 91 oncologic patients with immune checkpoint inhibitor (ICI)–induced pruritus, with 78% of them experiencing pruritus in association with a rash and 22% of them experiencing pruritus as the only symptom. Among patients with pruritus without rash, the most common first-line therapy was antihistamines (90%). Among patients with persistent pruritus (70%), the most common second-line therapy was phototherapy (35%). There was a statistically significant difference in mean pruritus Numerical Rating Scale (NRS) scores between baseline and after first-line and second-line interventions. Specifically, there was a significant decrease in mean NRS scores after phototherapy treatment.
• This study showed that a substantial proportion of patients (22%) can have ICI-induced pruritus without a rash. Dermatologic treatment using a variety of topical and systemic agents is effective in managing ICI-induced pruritus. In particular, phototherapy has been shown to be effective and can serve as an alternative to steroids and other immunomodulating agents.

–  Lillian Sun, MD

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Benjamin Hidalgo-Matlock
Skin Care Physicians of Costa Rica

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

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