Cutaneous vasculitis: palpable purpura and the AU general practice approach

What cutaneous vasculitis is

Cutaneous vasculitis is inflammation of blood vessel walls within the skin, most commonly affecting small post-capillary venules. The hallmark is palpable purpura — raised, non-blanching purple or dark-red spots, almost exclusively on dependent areas such as the calves, ankles, and dorsum of the feet, or the buttocks in children. Lesions are palpable because the inflamed vessel wall bleeds into the dermis; they do not blanch because the blood is extravascular, not intra-vascular.

Roughly half of adult cases are idiopathic and skin-limited, resolving within 3–6 weeks once any trigger is removed. The other half are secondary to drugs, infections, autoimmune disease, or malignancy. The primary task in general practice is to distinguish self-limited skin disease from systemic vasculitis with organ involvement, particularly kidney disease, which may be occult and requires prompt specialist coordination.

The 2012 Revised International Chapel Hill Consensus Conference (CHCC) classifies immune-complex-mediated small-vessel vasculitis — the group most relevant to general practice — into IgA vasculitis, cryoglobulinaemic vasculitis, hypocomplementaemic urticarial vasculitis syndrome (HUVS), and single-organ cutaneous small-vessel vasculitis (Sunderkotter dermatologic addendum 2018; Australasian College of Dermatologists (ACD) A-Z vasculitis). ANCA-associated vasculitis is a separate category covered in its own article.

A. Core clinical — the AU general-practice framework

History

The key questions follow from the pathophysiology of immune-complex deposition in venule walls:

Rash characteristics — when did it start, where first, has it spread? Palpable purpura on the calves and ankles is the expected pattern. Involvement above the waist, on the trunk, or involving mucous membranes raises concern for medium-vessel or ANCA-associated vasculitis and should prompt urgent specialist referral.

Preceding trigger 1–3 weeks earlier — new prescription (β-lactam antibiotic, NSAID, allopurinol, hydralazine, anti-TNF biologic, sulfonamide), URTI or sore throat (streptococcal IgA vasculitis), gastroenteritis, or recent vaccination. Over-the-counter and herbal supplement use — including echinacea and Chinese herbal preparations — has been associated with drug-induced vasculitis in case reports (eTG dermatology). Levamisole-adulterated cocaine produces a distinctive dual MPO/PR3-positive vasculopathy with ear-helix necrosis.

Systemic review — constitutional symptoms (fever, weight loss, night sweats → malignancy or connective tissue workup); GI symptoms (colicky abdominal pain, blood per rectum → bowel ischaemia or intussusception in paediatric IgA vasculitis); urinary symptoms (frothy urine, haematuria → renal vasculitis); joint symptoms (symmetrical large-joint arthralgia → IgA vasculitis, connective tissue disease); neurological symptoms (asymmetric foot or wrist weakness → mononeuritis multiplex); Raynaud phenomenon (cryoglobulin); and ENT symptoms such as nasal crusts or saddle nose deformity, which suggest granulomatosis with polyangiitis.

Relevant medical history — chronic hepatitis C or B, HIV, prior haematological malignancy or MGUS, autoimmune diagnoses (SLE, Sjögren syndrome, RA), inflammatory bowel disease, and any prior similar skin eruption.

Examination

• Skin — confirm the rash is truly palpable (senile purpura from skin fragility is macular); document distribution, whether lesions are iso-aged (single idiopathic episode) or mixed-aged (chronic relapsing disease), and morphology. Vesicles, pustules, or necrotising ulcers suggest deeper vessel involvement. Retiform (branching, net-like) purpura suggests medium-vessel disease or microvascular occlusion and warrants broader workup (BAD Goeser JEADV 2020).
• Blood pressure and bedside urinalysis — the single most informative GP test for systemic involvement. Haematuria plus proteinuria is renal vasculitis until proved otherwise; explicitly request dysmorphic red blood cells and casts on the microscopy request form.
• Cardiovascular — peripheral pulses, splinter haemorrhages, and any new cardiac murmur (endocarditis is an important mimic).
• Abdomen — tenderness, guarding, and mass; in children a sausage-shaped right-upper-quadrant mass suggests intussusception complicating IgA vasculitis.
• Neurological — asymmetric sensorimotor screen for mononeuritis multiplex (foot or wrist drop).

Investigations

Per BAD adult idiopathic cutaneous small-vessel vasculitis guideline (Goeser JEADV 2020) and eTG complete, the first-pass GP panel is:

Bloods: FBC with differential; UEC and eGFR; LFT; ESR and CRP; ANA, ENA, anti-dsDNA, RF; ANCA panel (IIF plus PR3 and MPO ELISA); complement C3 and C4; cryoglobulins (must be collected and transported warm at 37°C — cold handling precipitates the cryoglobulins before the laboratory can analyse them, producing false-negative results); serum protein electrophoresis with immunofixation and free light chains (exclude MGUS or lymphoma); hepatitis B surface antigen and core antibody; hepatitis C antibody and RNA PCR; HIV antibody; ASOT and anti-DNase B for suspected post-streptococcal trigger (especially in children and young adults); blood cultures if febrile.

Biopsy — the diagnostic cornerstone (BAD Goeser JEADV 2020; ACD A-Z vasculitis):

• 3–4 mm punch biopsy of a lesion under 24–48 hours old for H&E: leukocytoclastic vasculitis — neutrophilic perivascular infiltrate, nuclear karyorrhexis (nuclear dust), fibrinoid necrosis, and red blood cell extravasation.
• Second 3 mm sample from perilesional skin in Michel medium for direct immunofluorescence (DIF): IgA-dominant deposits confirm IgA vasculitis; IgM/IgG/C3 support idiopathic LCV; C1q plus immunoglobulin in HUVS; cryoglobulin granules in cryoglobulinaemic vasculitis. DIF sensitivity for IgA falls sharply after 48 hours — biopsy early; do not use a negative late biopsy to exclude IgA vasculitis.

MBS items for GP-performed biopsy: punch biopsy 30071. DIF is performed by a referral dermatopathology laboratory; specify the clinical context (palpable purpura, IgA vasculitis query) on the request to ensure the correct panel.

B. Subtype recognition — the differentiating features

The subtypes seen most commonly in AU general practice differ in aetiology, patient population, and renal risk:

Idiopathic single-organ cutaneous LCV accounts for roughly 50% of adult cases (BAD Goeser JEADV 2020). Peak age 50–70 years, slightly more common in women. Triggered by a drug or infection in many; idiopathic if workup is negative. Skin-limited and self-resolving in 3–6 weeks with supportive management. Persistent renal abnormality reclassifies the disease to a systemic subtype.

IgA vasculitis (formerly Henoch-Schönlein purpura) — predominantly paediatric; incidence approximately 20 per 100,000 children under 17 years, peak 4–7 years, autumn and winter clustering (Hetland Acta Derm Venereol 2017). The tetrad is palpable purpura, arthralgia (knees and ankles), colicky abdominal pain, and renal involvement. Adult IgA vasculitis is rare (~1 per 100,000 per year) but carries substantially worse renal prognosis — approximately 30% develop chronic kidney disease and 10–15% progress to end-stage kidney disease (Pillebout JASN 2002; Audemard-Verger Semin Arthritis Rheum 2017).

Cryoglobulinaemic vasculitis in Australia is overwhelmingly driven by hepatitis C virus type II mixed cryoglobulinaemia. The biochemical fingerprint is very low C4 with relatively preserved C3, plus a positive rheumatoid factor. Presentation includes purpura, livedo, ulcers, Raynaud phenomenon, and peripheral neuropathy. Since universal PBS access to direct-acting antivirals (DAAs) from March 2016, the incidence of HCV-driven cryoglobulinaemic vasculitis has fallen substantially (Australian Hepatitis C Strategy 2018–2022).

Hypocomplementaemic urticarial vasculitis (HUVS) presents as urticarial wheals lasting more than 24 hours (distinguishing it from ordinary urticaria), residual purpura, and burning rather than typical itch. Both C3 and C4 are low; anti-C1q antibodies are positive. Over 50% of HUVS patients have or develop SLE — systematic lupus workup is mandatory (Davis Curr Rheumatol Rep 2013).

Drug-induced vasculitis resolves in most cases once the culprit is stopped. Common culprits in AU include β-lactam antibiotics, NSAIDs, allopurinol, hydralazine, anti-TNF biologics, and sulfonamides. Report any drug-induced vasculitis to the TGA Database of Adverse Event Notifications (DAEN) and annotate the patient’s My Health Record with the suspected allergen.

C. Management

Step 1 — Remove the trigger

Stopping the suspect drug is the single highest-yield intervention and resolves approximately 30–50% of drug-induced cases without additional treatment. Treat any active infection: penicillin V for 10 days for a streptococcal trigger per eTG antibiotic (use amoxicillin only if penicillin itself was not the trigger). Initiate HCV testing and, where indicated, DAA therapy for any cryoglobulinaemic or unexplained LCV with positive HCV serology.

Step 2 — Skin-limited disease

Supportive management is first-line for idiopathic skin-limited LCV (BAD Goeser JEADV 2020):

• Rest with legs elevated at every opportunity
• Graduated compression stockings 18–25 mmHg (knee-high; private purchase, state equipment-scheme subsidies vary; contraindicated if ABPI < 0.8 or critical limb ischaemia is present)
• Simple analgesia with paracetamol; avoid NSAIDs until renal status is confirmed — NSAIDs perpetuate immune-complex injury and increase AKI risk
• Medium-potency topical corticosteroid (for example mometasone furoate 0.1% ointment once daily for up to 2 weeks) for itch or burning

Routine systemic corticosteroids for skin-only disease are not recommended — high relapse-on-taper rate, no reduction in cumulative disease duration, and significant steroid harms (Audemard-Verger Semin Arthritis Rheum 2017; BAD Goeser JEADV 2020). Most idiopathic LCV resolves in 3–6 weeks; post-inflammatory hyperpigmentation can persist for months.

Step 3 — Systemic involvement (joint, GI, or mild renal)

Oral prednisolone 0.5–1 mg/kg/day (typically 40–60 mg in an adult), tapered over 4–6 weeks per eTG rheumatology and AMH prednisolone monograph. If the anticipated course exceeds 3 months at ≥7.5 mg/day, initiate the bone-protection bundle — calcium, vitamin D, DXA, and bisphosphonate per RACGP osteoporosis 2024 guideline.

Step 4 — Severe or organ-threatening disease

Specialist-initiated only. Pulse intravenous methylprednisolone plus induction rituximab or cyclophosphamide for rapidly progressive glomerulonephritis, alveolar haemorrhage, or mononeuritis multiplex (RAVE Stone NEJM 2010). Mandatory TMP-SMX 160/800 mg three times weekly for Pneumocystis prophylaxis while on high-dose immunosuppression.

Step 5 — Chronic or refractory cutaneous LCV (>3 months, ≥2 relapses)

Colchicine 0.5 mg twice daily — supported by a small randomised trial (Sais JAAD 2004) and endorsed as a steroid-sparing option in the BAD 2020 guideline. PBS Authority Required (familial Mediterranean fever indication); off-label for cutaneous vasculitis. Well tolerated; GI intolerance limits use in some patients. Reduce dose in renal impairment to avoid myopathy and neuropathy.

Dapsone 50–100 mg/day — case-series evidence; check G6PD status before prescribing to avoid haemolysis. Monitor FBC, LFT, and methaemoglobin. General PBS schedule; no Authority required.

Hydroxychloroquine 200–400 mg/day — particularly useful when there is connective tissue disease overlap (SLE, Sjögren syndrome); baseline and annual ophthalmology surveillance per RANZCO guidance. PBS Authority Required for RA and SLE indications; off-label for cutaneous vasculitis.

Step 6 — Cryoglobulinaemic vasculitis

Treat underlying HCV with sofosbuvir-based DAAs — PBS Section 100 Highly Specialised Drugs program with universal access since March 2016; any GP can prescribe after meeting the brief remote-consultation criteria. Sustained virological response is achieved in over 95% of people and induces vasculitis remission in approximately 80% (Saadoun Ann Rheum Dis 2016). Check for DAA-drug interactions before prescribing (amiodarone, statins, and anticonvulsants are clinically significant). Severe organ-threatening cryoglobulinaemic vasculitis warrants rituximab plus corticosteroid alongside DAA therapy, initiated by a specialist.

D. Australian operations

MBS items relevant in general practice:

• GP consultation: Level B 23, C 36, D 44
• FBC 66512; UEC 66500; urinalysis plus microscopy 66503; urine ACR 66319
• ANA/ENA/dsDNA 71161; ANCA plus PR3 and MPO 73529; complement C3/C4 71165; serum protein electrophoresis 66635
• HCV antibody plus RNA PCR 69445 / 69499; HIV 69384; HBV serology 69481
• Skin punch biopsy 30071; DIF is claimed by the referral dermatopathology laboratory
• GPCCMP preparation 965 / review 967 for chronic relapsing disease; 3-monthly target
• Mental Health Care Plan 2715 / review 2717 for chronic disfiguring skin disease, steroid mood, or adjustment disorder

PBS authority codes:

• Prednisolone — general PBS schedule, no authority required
• Colchicine — Authority Required (familial Mediterranean fever); off-label for vasculitis
• Dapsone — general schedule; G6PD check before prescribing
• Hydroxychloroquine — Authority Required for RA and SLE; off-label for cutaneous vasculitis
• HCV DAAs — Section 100 Highly Specialised Drugs, universal access since March 2016
• Rituximab — Section 100 Authority Required for AAV specifically; not PBS-funded for idiopathic LCV or IgA vasculitis nephritis — compassionate access or private funding required for non-AAV indications
• Bisphosphonates — Authority Required if T-score ≤−1.5 and prednisolone ≥7.5 mg/day for ≥3 months

Notifiable conditions — HBV, HCV, and HIV are notifiable if newly diagnosed during the vasculitis workup. Coordinate partner notification for HCV per state public-health legislation.

GPCCMP eligibility — chronic relapsing cutaneous vasculitis, IgA vasculitis nephritis, and post-HCV cryoglobulinaemia all qualify. The MDT plan should include dermatology, nephrology, and rheumatology or immunology, plus at minimum psychology (body image, chronic illness adjustment, steroid mood) and exercise physiology (steroid myopathy, deconditioning, cardiovascular risk).

Telehealth — existing 12-month GP relationship rule applies; appropriate for stable maintenance visits, medication monitoring reviews, and pathology result discussions.

TGA DAEN reporting — any suspected drug-induced vasculitis should be reported to the TGA DAEN and recorded as an allergy or adverse drug reaction in the patient’s practice software and My Health Record.

E. Special populations

Paediatric IgA vasculitis — supportive management alone for approximately 95% of children: paracetamol for analgesia (avoid NSAIDs if renal involvement), rest, hydration, and parental education (Ozen EULAR/PRINTO/PRES Ann Rheum Dis 2010). Oral prednisolone shortens abdominal pain and arthritis duration but does not prevent renal disease per multiple paediatric RCTs and Cochrane review — do not prescribe solely to protect the kidneys. Renal surveillance protocol: urinalysis and blood pressure weekly for 4 weeks, then fortnightly for 2 months, then monthly for 6 months minimum. Refer paediatric nephrology promptly if proteinuria exceeds +1 on dipstick, frank haematuria, hypertension, or rising creatinine.

Adult IgA vasculitis — nephrology shared care from the outset, given the substantially worse renal prognosis compared with paediatric disease. ACEi or ARB for proteinuria; consider SGLT2 inhibitor co-prescription in line with emerging IgA nephropathy evidence; immunosuppression for crescentic glomerulonephritis.

Older adults — higher prevalence of drug triggers and occult malignancy as the aetiology of new idiopathic LCV. Systematic age-appropriate cancer screen (FOBT or FIT, CXR, SPEP, gender-appropriate screening currency) for any adult over 50 with new unexplained palpable purpura (BAD Goeser JEADV 2020). Confirm ABPI before prescribing compression stockings — peripheral arterial disease is more prevalent in this age group.

Aboriginal and Torres Strait Islander patients — under-represented in vasculitis registries; renal trajectories are worsened by late presentation and access barriers. Coordinate with the ATSI health assessment framework and Aboriginal Liaison Officer. Telehealth monitoring visits reduce travel burden for remote patients.

Pregnancy — cutaneous vasculitis in pregnancy requires specialist shared care. Most immunosuppressives carry fetal risk; colchicine is classified TGA Category A and is generally regarded as safe. DAA therapy for HCV is usually deferred post-partum unless disease severity is compelling; specialist hepatology input required for any decision to treat during pregnancy.

When to escalate

Urgent or emergency — same day:

• Oliguria, rising creatinine, or hyperkalaemia → suspected rapidly progressive glomerulonephritis
• Haemoptysis plus AKI → pulmonary-renal syndrome
• Severe abdominal pain with peritonism → intussusception or bowel ischaemia in paediatric IgA vasculitis
• Rapidly spreading skin necrosis or new foot or wrist drop (mononeuritis multiplex)

Semi-urgent — within one week:

• Any new palpable purpura in an adult — dermatology referral and punch biopsy (MBS 30071)
• New IgA vasculitis with proteinuria or haematuria — nephrology
• Positive cryoglobulin — immunology or rheumatology and infectious diseases for HCV assessment
• Urticarial lesions lasting more than 24 hours with low complement — rheumatology for HUVS and SLE workup

Routine:

• Stable chronic relapsing cutaneous LCV — dermatology
• Paediatric IgA vasculitis post-acute phase — paediatric nephrology for long-term renal surveillance

What this article is and is not

This is general health information drawn from current Australian general practice guidelines — Therapeutic Guidelines, AMH, RACGP, the British Association of Dermatologists 2020 guideline, the Australasian College of Dermatologists, and EULAR/PRES classification criteria. It is not personal medical advice and does not create a doctor–patient relationship. Diagnostic and treatment decisions are made with your own GP and treating specialists.

For Australian consumer information: HealthDirect — vasculitis, Better Health Channel — purpura, Vasculitis Foundation Australia, Hepatitis Australia, ACD A-Z vasculitis.

For urgent after-hours advice: HealthDirect nurse-on-call 1800 022 222.

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Sources cited

1. Sunderkotter CH et al. Nomenclature of cutaneous vasculitis — Dermatologic Addendum to 2012 CHCC. Arthritis Rheumatol 2018
2. Goeser MR et al. BAD guidelines for adults with idiopathic cutaneous small-vessel vasculitis. JEADV 2020
3. Ozen S et al. EULAR/PRINTO/PRES Ankara 2008 criteria for IgA vasculitis. Ann Rheum Dis 2010
4. Pillebout E et al. Henoch-Schönlein purpura in adults — outcome and prognostic factors. J Am Soc Nephrol 2002
5. Audemard-Verger A et al. Adult IgA vasculitis — French nationwide cohort. Semin Arthritis Rheum 2017
6. Saadoun D et al. Sofosbuvir for HCV cryoglobulinaemic vasculitis (VASCUVALDIC). Ann Rheum Dis 2016
7. Sais G et al. Colchicine for cutaneous leukocytoclastic vasculitis. JAAD 2004
8. Stone JH et al. RAVE — rituximab vs cyclophosphamide for AAV. NEJM 2010
9. Davis MDP et al. Urticarial vasculitis and HUVS. Curr Rheumatol Rep 2013
10. Hetland LE et al. Henoch-Schönlein purpura — literature review. Acta Derm Venereol 2017
11. Australasian College of Dermatologists — A-Z of Skin: Vasculitis
12. Therapeutic Guidelines (eTG complete) — Dermatology / Rheumatology / Antibiotic
13. Australian Medicines Handbook 2025
14. Australian Hepatitis C Strategy 2018–2022 and PBS universal DAA access
15. RACGP — osteoporosis prevention and management 2024
16. TGA DAEN — drug-induced vasculitis reporting
17. HealthDirect — Vasculitis
18. Better Health Channel — Purpura
19. MBS Online — items 23/36/44, 66500/66503/66319/66512/66635, 71161/71165, 73529, 69384/69445/69481/69499, 30071, 965/967, 2715/2717