Table 2.

Skin irAE: management algorithm.

Dermatology irAE	Investigations	Management
Grade 1/mild
Rash < 10% body surface area (BSA), pruritus		Continue checkpoint inhibitor therapy General skin care measures: Avoid irritants: soap and excess water Emollients: creams and ointments Oral antihistamines: Nonsedating (daytime); sedating (nocte) Topical corticosteroids (moderate potency, ointment > cream vehicle) Phototherapy for pruritus: short course narrow band UVB, for example, 3x week for 4 weeks (relatively contraindicated with history of melanoma)
Grade 2/moderate
Rash (10–30% BSA), pruritus	Skin swabs MCS, viral PCR, scrapings (fungal KOH) Prolonged symptoms (1-2 weeks): consider skin biopsy	Continue checkpoint inhibitor therapy Consider dermatology review General skin care measures and emollients as above Oral antihistamines (increased dosing may be required: 2–4x standard dose), depending on renal and liver function Topical corticosteroid (moderate to very potent, ointment > cream vehicle) Wet dressings (educate at outpatient dermatology treatment centre) Prolonged symptoms: Delay immunotherapy until resolving to ≤ Grade 1 Prednisolone 0.5–1 mg/kg/day with slow taper Consider hospital admission for wet dressings Refractory pruritus:   Consider neuropathic analgesia, for example, pregabalin 25 mg daily and titrate to response
Grade 3-4/severe/life-threatening
Rash (≥30% BSA), pruritus, blisters, ulceration	Skin biopsy (with direct immunofluorescence if blisters present)	Delay immunotherapy if Grade 3 until resolving to Grade ≤ 1 Cease immunotherapy if SJS/TEN (Grade 4) Urgent dermatology review and biopsy Prednisolone 1 mg/kg/day or pulse with methylprednisolone 1-2 mg/kg/day for 3 days∗Consideration of IVIG and/or cyclosporin Transfer to burns unit if skin loss > 10%

^∗Switch to oral prednisolone 1 mg/kg/day with slow taper over 1 month or longer. PJP (e.g., bactrim DS 1/2 tablet daily) and GIT ulcer prophylaxis therapy when patients are on prolonged steroid taper. Monitor blood glucose.