Polyarteritis nodosa

What it is

From: Orphanet

A rare, clinically heterogeneous, systemic disease characterized by necrotizing inflammatory lesions affecting medium-sized blood vessels. It most commonly affects skin, joints, peripheral nerves and the gastrointestinal tract.

Reported clinical features and what the terms mean

The following findings are associated with this condition in Orphanet. They are not a checklist for diagnosing yourself, and they do not all occur in every affected person. Some are examination, imaging or laboratory findings that cannot be recognised at home.

The frequency labels describe how often a finding was reported among people with the condition in the source. They do not give the chance that a person with that symptom has the condition. Definitions below reproduce HPO terminology; they explain the term, not the likely severity in an individual.

Abnormal skin morphology · Very frequent (99-80%)

Any morphological abnormality of the skin.

Abnormality of the kidney · Frequent (79-30%)

An abnormality of the kidney.

Arthralgia · Frequent (79-30%)

Joint pain.

Elevated circulating C-reactive protein concentration · Frequent (79-30%)

The concentration of C-reactive protein in the blood circulation is above the upper limit of normal.

Fever · Frequent (79-30%)

Body temperature elevated above the normal range.

Livedo racemosa · Frequent (79-30%)

Livedo racemosa describes a reddish-blue mottling of the skin in an irregular, reticular pattern. It differs from the more common livedo reticularis by its shape. Livedo racemosa consists of broken circular segments resulting in a seemingly larger pattern, as opposed to the fine, regular, complete network of livedo reticularis. Livedo racemosa results from permanent impairment of peripheral blood flow and, unlike livedo reticularis, it persists on warming.

Myalgia · Frequent (79-30%)

Pain in muscle.

Peripheral neuropathy · Frequent (79-30%)

Peripheral neuropathy is a general term for any disorder of the peripheral nervous system. The main clinical features used to classify peripheral neuropathy are distribution, type (mainly demyelinating versus mainly axonal), duration, and course.

Polyneuritis · Frequent (79-30%)

Simultaneous inflammation of multiple nerves.

Weight loss · Frequent (79-30%)

Reduction of total body weight.

Polyarticular arthritis · Frequent (79-30%)

Abdominal pain · Occasional (29-5%)

An unpleasant sensation characterized by physical discomfort (such as pricking, throbbing, or aching) and perceived to originate in the abdomen.

Abnormal cardiovascular system morphology · Occasional (29-5%)

Any structural anomaly of the heart and blood vessels.

Abnormal lung morphology · Occasional (29-5%)

Any structural anomaly of the lung.

Other findings in the same source

From: Orphanet

Additional reported features include Abnormality of the gastrointestinal tract (Occasional (29-5%)); Abnormality of the nervous system (Occasional (29-5%)); Cutis marmorata (Occasional (29-5%)); Erythema (Occasional (29-5%)); Hypertension (Occasional (29-5%)); Morphological central nervous system abnormality (Occasional (29-5%)); Pericarditis (Occasional (29-5%)); Sensory axonal neuropathy (Occasional (29-5%)); Skin ulcer (Occasional (29-5%)); Subcutaneous nodule (Occasional (29-5%)). This is a selected summary, not a complete description of the condition.

When it may begin

From: Orphanet

All ages

Inheritance in the source

From: Orphanet

Not applicable

Frequency and the population described

From: Orphanet

Point prevalence: 1-9 / 100 000; Europe; Value and class. Point prevalence: 1-9 / 100 000; Sweden; Value and class. Point prevalence: 1-9 / 100 000; France; Value and class. Annual incidence: 1-9 / 1 000 000; Australia; Value and class.

Which doctor should you see?

The suggested department for discussing Polyarteritis nodosa is Rheumatology, with a rheumatologist as the relevant type of clinician. General physician / Family Medicine; paediatrician for children. Referral depends on symptoms.

This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.

How to prepare for an assessment

Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.

Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.

• Are the findings inflammatory, structural or due to another mechanism?
• Is there evidence that other organs need assessment?
• How will function and any treatment-related risks be monitored?

Treatment discussions and follow-up

The material gathered for this draft does not provide a complete condition-specific treatment pathway for Polyarteritis nodosa. That gap does not mean that treatment is unavailable. A clinician needs to establish the diagnosis and review current guidance before recommending medicines, procedures, rehabilitation or other support.

Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.

The collected references do not establish a complete prevention or long-term outlook section for this entry. Missing information should not be interpreted as proof that prevention is impossible or that a particular outcome is inevitable. Ask what is known for the exact subtype, stage and personal circumstances, and which uncertainties remain.

When to seek emergency help

Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.