# Immune-related skin reactions from checkpoint inhibitors, including blistering and severe erosive rashes

Source: https://onco.cc/protocols/irae-skin/  
OnCo record `irae-skin` (Protocol). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Rash and itching are among the commonest and earliest side effects of immunotherapy, usually a few weeks in, and most are mild. Blisters, peeling skin, sore skin, or sores in the mouth, eyes or genitals are different: they can be serious and need the cancer team the same day.

## Summary

Rash occurs in 23% on anti-CTLA-4 (1% grade 3 or more), 10% on anti-PD-(L)1 and 41% on combinations (5% grade 3 or more), on average 3 to 4 weeks after starting (SITC 2021). Rare severe forms include bullous pemphigoid (about 1% on anti-PD-(L)1), pemphigus, lichenoid eruptions and SJS/TEN, which has mucosal involvement and can arise suddenly or evolve from a lichenoid rash that fails treatment.

SITC 2021: for itch without rash, high-potency topical steroids and GABA agonists may be considered (LE: 4). Work up rash with blood count, metabolic panel, percentage of body surface affected, special features (blisters, mucosal involvement) and allergy history; consider dermatology referral, and for grade 3 or more refer and consider biopsy. Blisters or mucosal involvement trigger biopsy with direct immunofluorescence and serology for pemphigus and pemphigoid. Interrupt the checkpoint inhibitor until resolution or significant improvement. Refer to dermatology if topical or oral steroids fail, the rash is grade 3 or more, or intolerable. For rashes that recur on taper, a steroid-sparing drug matched to the diagnosis: rituximab for pemphigus (LE: 1) or bullous pemphigoid (LE: 4), dupilumab for eczema (LE: 1), infliximab for lichenoid rash, omalizumab for urticaria or itch (LE: 1). Re-challenge after grade 3 rash is possible. A rash not responding to immunosuppression may be infected.

The 2024 D-irAE consensus separates ICI-erosive mucocutaneous disease, including an SJS/TEN-like acute form, from classic SJS/TEN and says it usually means at least holding and often permanently stopping the checkpoint inhibitor. ESMO 2022 could not be read.

## Fields

- Kind: Protocol
- Last checked: 2026-11-11
- Also known as: checkpoint inhibitor rash; immunotherapy skin toxicity; ICI bullous pemphigoid; ICI SJS/TEN; dermatologic irAE; D-irAE
- Tags: protocol; irae; dermatology

## Connected records

- protocols: [Baseline tests and monitoring before and during checkpoint inhibitor treatment](https://onco.cc/protocols/checkpoint-inhibitor-baseline-and-monitoring/), [Immune-related diarrhoea and colitis from checkpoint inhibitors, by grade](https://onco.cc/protocols/irae-colitis/)
- technologies: [Immune checkpoint inhibitors](https://onco.cc/technologies/checkpoint-inhibitor/)
- drugs: [Atezolizumab](https://onco.cc/drugs/atezolizumab/), [Avelumab](https://onco.cc/drugs/avelumab/), [Cemiplimab](https://onco.cc/drugs/cemiplimab/), [Dostarlimab](https://onco.cc/drugs/dostarlimab/), [Durvalumab](https://onco.cc/drugs/durvalumab/), [Ipilimumab](https://onco.cc/drugs/ipilimumab/), [Nivolumab](https://onco.cc/drugs/nivolumab/), [Pembrolizumab](https://onco.cc/drugs/pembrolizumab/), [Rituximab](https://onco.cc/drugs/rituximab/), [Tremelimumab](https://onco.cc/drugs/tremelimumab/)
- institutions: [American Society of Clinical Oncology (ASCO)](https://onco.cc/institutions/asco/), [European Society for Medical Oncology (ESMO)](https://onco.cc/institutions/esmo/), [Society for Immunotherapy of Cancer](https://onco.cc/institutions/sitc/)
- terms: [Immune-related adverse events (irAEs)](https://onco.cc/terms/irae/)

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