Synopsis
Prevent, recognise and safely manage cutaneous and disseminated infection in people receiving immune-modifying treatment, while distinguishing routine precautions from emergencies and avoiding abrupt corticosteroid withdrawal or dangerous antimicrobial interactions.
- Define the regimen precisely: infection risk depends on mechanism, dose, duration, combination treatment, comorbidity and residual drug half-life rather than the label immunosuppressed alone.
- Ask about tuberculosis, hepatitis, HIV, previous varicella or zoster, recurrent HSV, chronic wounds, diabetes, travel, exposure and vaccination before treatment begins.
- Complete indicated vaccines before immune suppression where possible; non-live vaccines are generally safe, whereas live vaccines require Green Book and agent-specific timing.
- Teach people to report fever, rapidly changing painful skin, grouped vesicles, eye symptoms, oral ulcers, cough, dysuria or diarrhoea early because treatment can blunt typical inflammation.
- Bacterial cellulitis and impetigo, dermatophyte or Candida infection, HSV and varicella-zoster are common; atypical mycobacteria, invasive fungi and other opportunists need targeted sampling and specialist care.
- A localised eruption can announce systemic disease: multidermatomal zoster, eczema herpeticum, ecthyma gangrenosum and necrotising infection must not be managed as routine dermatitis.
- Withhold methotrexate, ciclosporin, a biologic or a JAK inhibitor during a serious infection and seek the prescribing team's restart plan; a long half-life means risk does not stop immediately.
- Do not abruptly stop long-term systemic corticosteroid during infection; assess adrenal suppression and provide the usual dose or stress-dose replacement while treating sepsis.
- Check interactions before prescribing: trimethoprim or co-trimoxazole can cause severe marrow toxicity with methotrexate, while macrolides and azoles can raise ciclosporin exposure.
- Antimicrobial prophylaxis is risk-stratified for a defined pathogen and regimen; routine antibiotics for every immunosuppressed person promote resistance and do not replace rapid assessment.
Key red flags
Disproportionate pain, rapid extension, skin anaesthesia, dusky or necrotic change, crepitus, hypotension, confusion, breathlessness, disseminated vesicles, forehead or eye involvement, severe mucosal disease, profound neutropenia, or infection soon after high-dose immune suppression requires same-day emergency care.
New functional decline, confusion, tachypnoea, hypotension or rigors can be more informative than absent fever, normal neutrophils or modest CRP after immune suppression.
Investigation priorities
Identify preventable and reactivatable infection before immune suppression.
Management branches
A systemic immune-modifying medicine is planned or intensified.
- Define drug, dose, combinations and expected duration and identify age, comorbidity, exposure, wound, travel and previous-infection modifiers.
- Complete the agent-specific TB, viral and laboratory screen, treat active infection and refer latent TB or hepatitis risk before starting.
- Offer indicated non-live vaccines and arrange any required live vaccine before therapy with the correct Green Book and SmPC interval.
- Give written early-warning, contact, medicine-withholding, food, travel, occupational and household-vaccine advice and record the responsible service.
A lesion progresses despite appropriate standard therapy or has nodular, deep or sporotrichoid morphology.
- Recheck diagnosis, adherence, antimicrobial dose, source control, resistance, foreign material and the full degree of immune compromise.
- Stop repeatedly swabbing the surface and obtain imaging or a deep biopsy with separately handled tissue for histology and broad microbiological culture.
- Ask microbiology or infectious diseases to direct incubation, molecular testing and prolonged therapy for fungi, mycobacteria or other opportunists.