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Educational draft · awaiting clinical reviewUse Rapid for revision, not patient-care decisions. Check current national and local guidance and the BNF or BNFC before acting.

Calciphylaxis

Dermatology · UK scope · Sources checked 27 Aug 2026 · Clinical review pending

RapidFull
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Painful necrosis with infection risk

Rapidly progressive retiform necrosis, severe pain, fever, hypotension, spreading erythema, purulence, crepitus, wet gangrene or a deteriorating dialysis patient may have calciphylaxis with superimposed cellulitis, sepsis or necrotising infection, a major cause of early death.

Action: Admit for ABCDE and sepsis care, urgent nephrology, dermatology, tissue-viability, pain and surgical assessment, culture and image as appropriate and begin antimicrobials and source control when infection is credible without delaying calciphylaxis-directed management.

Synopsis

Recognise painful calcific arteriolopathy before black necrosis appears, distinguish it from infection and other retiform disease, and coordinate urgent renal, wound, analgesic, metabolic and infection management despite limited treatment evidence.

  • Calciphylaxis is calcific uraemic arteriolopathy: an uncommon, intensely painful occlusive small-artery disease seen mainly in advanced CKD and dialysis, although non-uraemic cases occur.
  • Deep burning pain and firm woody subcutaneous induration can precede visible change; lesions evolve through mottled livedoid or retiform purple-grey plaques to ulcer and black eschar.
  • On brown or black skin, early colour may be deep violet, grey-brown or subtle; exquisite focal pain, hardness, temperature and an angular vascular outline should trigger examination under good light and touch.
  • Risk rises with dialysis duration, diabetes, obesity, female sex, hypoalbuminaemia, severe CKD-mineral disorder, warfarin, calcium loading, injection trauma and systemic inflammation, but normal calcium or phosphate does not exclude disease.
  • Diagnosis is clinical and multidisciplinary; there is no perfectly sensitive gold-standard test. Deep edge biopsy can show calcified thrombosed arterioles but may cause a non-healing ulcer, infection or false-negative result.
  • First-line action is not one drug: control pain, search for infection, optimise dialysis and calcium–phosphate–PTH management, review promoting medicines and deliver expert wound care concurrently.
  • Sodium thiosulfate is widely used off-label, commonly after haemodialysis, but controlled efficacy evidence remains uncertain and metabolic acidosis, hypotension, nausea, sodium load and QT effects require monitoring.
  • Review warfarin urgently with the anticoagulation indication owner; do not stop it unsafely or assume substitution is straightforward in mechanical valves or high-risk APS.
  • Debridement is individualised: infected wet necrosis may need surgical source control, whereas dry stable eschar with poor perfusion can be harmed by reflex excision.
  • Early palliative and psychological support complements active treatment because pain, mortality and prolonged wound burden are severe; it does not signal abandonment.

    • Key red flags

    Pain out of proportion, rapidly enlarging livedoid or retiform plaques, black eschar, new systemic illness, crepitus, hypotension, exposed deep tissue, genital involvement, uncontrolled opioid-resistant pain or acute tissue ischaemia requires same-day multidisciplinary escalation.

    Necrotic ulcer and eschar

    A painful irregular ulcer exposes yellow-black fat and develops adherent black eschar, with a high risk of bacterial invasion and sepsis.

    Systemic infection overlay

    New warmth, spreading erythema, purulence, crepitus, fever, delirium or hypotension over a necrotic lesion indicates invasive infection until proved otherwise.

    Investigation priorities

    01
    Clinical risk and full-skin assessmentFirst step

    Recognise the syndrome early and document distribution before ulceration obscures the active edge.

    Management branches

    First-line recognition sequenceAct on pain and induration before eschar

    A dialysis or high-risk patient develops new focal severe skin pain, hardness or livedoid change.

    1. Examine the complete painful region and all skin with consent, document depth, temperature, retiform outline and infection and assess ABCDE and limb perfusion.
    2. Contact nephrology and dermatology the same day and involve tissue viability and pain specialists before waiting for ulceration or a biopsy appointment.
    3. Obtain mineral, inflammatory, renal, liver, nutrition, coagulation and infection baselines and decide collectively whether clinical certainty is sufficient or deep edge tissue will alter management.

    Key medicines

    Intravenous sodium thiosulfateA common off-label haemodialysis regimen is 25 g intravenously during the final hour of or immediately after each dialysis session three times weekly, using a lower starting dose when body size or tolerance requires it.Monitor bicarbonate and anion gap, sodium and calcium, blood pressure, volume, nausea, QT risk and venous access. Severe metabolic acidosis, hypotension, vomiting or sodium overload requires dose reduction or cessation; non-dialysis dosing needs specialist pharmacokinetic planning.
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    Sources and review status3 sources · checked 27 Aug 2026 · clinical review pending+
    Sources

    Sources and review status

    National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 27 Aug 2026; clinical approval remains outstanding.

    • Primary Care Dermatology Society calciphylaxisUK early morphology, risk factors, investigations, wound care and multidisciplinary treatment.
    • European Renal Association calciphylaxis updateCurrent diagnosis, biopsy trade-offs, treatment bundle, sodium thiosulfate uncertainty and research priorities.
    • NICE NG203 chronic kidney diseaseUK phosphate, calcium, vitamin D, PTH and dialysis-related CKD management context.

    Editorial contact: Doctor’s Passport editorial team. Source-check date is separate from clinical approval. Report a content problem · Content changes

    Authoring stateRapid draftClinical stateAwaiting reviewJurisdictionUnited Kingdom