Initial signs are extremely variable, and diagnosis can be severely delayed due to the nonspecific nature of the symptoms. In general, rhinitis is the first sign in most people.

- Kidney: rapidly progressive glomerulonephritis (75%), leading to chronic kidney failure

- Upper airway, eye and ear disease:

- Nose: pain, stuffiness, nosebleeds, rhinitis, crusting, "saddle-nose" deformity due to a perforated septum

- Ears: conductive hearing loss due to auditory tube dysfunction, sensorineural hearing loss (unclear mechanism)

- Oral cavity: strawberry gingivitis, underlying bone destruction with loosening of teeth, non-specific ulcerations throughout oral mucosa

- Eyes: pseudotumours, scleritis, conjunctivitis, uveitis, episcleritis

- Trachea: subglottal stenosis

- Lungs: pulmonary nodules (referred to as "coin lesions"), infiltrates (often interpreted as pneumonia), cavitary lesions, pulmonary haemorrhage causing haemoptysis, and rarely bronchial stenosis.

- Arthritis: Pain or swelling (60%), often initially diagnosed as rheumatoid arthritis

- Skin: nodules on the elbow, purpura, various others (see "cutaneous vasculitis")

- Nervous system: occasionally sensory neuropathy (10%) and rarely mononeuritis multiplex

- Heart, gastrointestinal tract, brain, other organs: rarely affected.

The second stage is characterized by an abnormally high level of eosinophils (a type of white blood cell) in the blood and tissues. The symptoms of hypereosinophilia depend on which part of the body is affected, but most often it affects the lungs and digestive tract. The signs and symptoms of hypereosinophilia may include weight loss, night sweats, asthma, cough, abdominal pain, and gastrointestinal bleeding. Fever and malaise are often present.

The eosinophilic stage can last months or years, and its symptoms can disappear, only to return later. Patients may experience the third stage simultaneously.

Ophthalmic examination may reveal neovascularization (creation of new vessels in the retina), retinal vessel narrowing, retinal vessel cuffing, retinal hemorrhage, or possible vitritis (inflammation of the vitreous body) or choroiditis (inflammation of the choroid).

The prodromal stage is characterized by allergy. Almost all patients experience asthma and/or allergic rhinitis, with more than 90% having a history of asthma that is either a new development, or the worsening of pre-existing asthma, which may require systemic corticosteroid treatment. On average, asthma develops from three to nine years before the other signs and symptoms.

The allergic rhinitis may produce symptoms such as rhinorrhea and nasal obstruction, and the formation of nasal polyps that require surgical removal, often more than once. Sinusitis may also be present.

Retinal vasculitis is very rare as the only presenting symptom. Often there is sufficient systemic evidence to help the physician decide between any one of the aforementioned possible systemic diseases. For those patients who present with only vasculitis of the retinal vessels, great investigative effort (Chest X-ray, blood test, urinary analysis, vascular biopsy, ophthalmology assessment, etc.) should be undertaken to ensure that a systemic disease is not the hidden culprit.

Uveitis is classified anatomically into anterior, intermediate, posterior, and panuveitic forms—based on the part of the eye primarily affected. Prior to the twentieth century, uveitis was typically referred to in English as "ophthalmia."

- Anterior uveitis includes iridocyclitis and iritis. Iritis is the inflammation of the anterior chamber and iris. Iridocyclitis presents the same symptoms as iritis, but also includes inflammation in the ciliary body. Anywhere from two-thirds to 90% of uveitis cases are anterior in location. This condition can occur as a single episode and subside with proper treatment or may take on a recurrent or chronic nature.

- intermediate uveitis, also known as pars planitis, consists of vitritis—which is inflammation of cells in the vitreous cavity, sometimes with "snowbanking", or deposition of inflammatory material on the pars plana. There are also "snowballs," which are inflammatory cells in the vitreous.

- Posterior uveitis or chorioretinitis is the inflammation of the retina and choroid.

- Pan-uveitis is the inflammation of all layers of the uvea.

Most common:

- Floaters

- Blurred vision

Intermediate uveitis normally only affects one eye. Less common is the presence of pain and photophobia.

Possible symptoms include:

- General symptoms: Fever, weight loss

- Skin: Palpable purpura, livedo reticularis

- Muscles and joints: Myalgia or myositis, arthralgia or arthritis

- Nervous system: Mononeuritis multiplex, headache, stroke, tinnitus, reduced visual acuity, acute visual loss

- Heart and arteries: Myocardial infarction, hypertension, gangrene

- Respiratory tract: Nose bleeds, bloody cough, lung infiltrates

- GI tract: Abdominal pain, bloody stool, perforations

- Kidneys: Glomerulonephritis

Hypersensitivity vasculitis (allergic vasculitis). Usually due to a hypersensitivity reaction to a known drug. Drugs most commonly implicated are penicillin, sulphonamides and thiazide diuretics. There is presence of skin vaculitis with palpable petechiae or purpura. Biopsy of these lesions reveal inflammation of the small vessels, termed leukocytoclastic vasculitis, which is most prominent in postcapillary venules. At least 3 out of 5 criteria yields sensitivity and specificity of 71 and 84%:

- age > 16

- use of possible triggering drug in relation to symptoms

- palpable purpura

- maculopapular rash

- skin biopsy showing neutrophils around vessel

IgA vasculitis (IgAV; formerly known as Henoch-Schonlein purpura). Systemic vasculitis due to tissue deposition of IgA-containing immune complexes. Biopsy of lesions shows inflammation of small vessels. It is considered a form of hypersensitivity vasculitis but is distinguished by prominent deposits of IgA. This is the most common vasculitis in children. Presence of 3 or more criteria yielded sensitivity of 87% while less than 2 criteria yielded hypersensitivity vasculitis in 74%:

- palpable purpura (usually of buttocks & legs)

- bowel angina

- GI bleed

- hematuria

- onset < 20 years

- no new medications

Essential cryoglobulinemic vasculitis. Most often due to hepatitis C infection, immune complexes of cryoglobulins --- proteins that consists of immunoglobulins and complement and precipitate in the cold while dissolving upon rewarming --- are deposited in walls of capillaries, venules, or arterioles. Therefore, complement will be low with histology showing vessel inflammation with immune deposits.

Granulomatosis with polyangiitis (GPA), formerly known as Wegener's granulomatosis (WG), is a systemic disorder that involves both granulomatosis and . It is a form of vasculitis (inflammation of blood vessels) that affects small- and medium-size vessels in many organs. Damage to the lungs and kidneys can be fatal. Treatment requires long-term immunosuppression.

Granulomatosis with polyangiitis is part of a larger group of vasculitic syndromes called systemic vasculitides or necrotizing vasculopathies, all of which feature an autoimmune attack by an abnormal type of circulating antibody termed ANCAs (antineutrophil cytoplasmic antibodies) against small and medium-size blood vessels. Apart from GPA, this category includes eosinophilic granulomatosis with polyangiitis (EGPA) and microscopic polyangiitis. Although GPA affects small- and medium-size vessels, it is formally classified as one of the small vessel vasculitides in the Chapel Hill system.

Symptoms of scleritis include:

- Redness of the sclera and conjunctiva, sometimes changing to a purple hue

- Severe ocular pain, which may radiate to the temple or jaw. The pain is often described as deep or boring.

- Photophobia and tearing

- Decrease in visual acuity, possibly leading to blindness

The pain of episcleritis is less severe than in scleritis. In hyperemia, there is a visible increase in the blood flow to the sclera (hyperaemia), which accounts for the redness of the eye. Unlike in conjunctivitis, this redness will not move with gentle pressure to the conjunctiva.

Patients usually present with systemic symptoms with single or multiorgan dysfunction. Common (and nonspecific) complaints include fatigue, weakness, fever, arthralgias, abdominal pain, hypertension, renal insufficiency, and neurologic dysfunction. The following symptoms should raise a strong suspicion of a vasculitis:

- Mononeuritis multiplex. Also known as asymmetric polyneuropathy, in a non-diabetic this is suggestive of vasculitis.

- Palpable purpura. If patients have this in isolation, it is most likely due to cutaneous leukocytoclastic vasculitis. If the purpura is in combination with systemic organ involvement, it is most likely to be Henoch-Schonlein purpura or microscopic polyarteritis.

- Pulmonary-renal syndrome. Individuals who are coughing up blood and have kidney involvement are likely to have granulomatosis with polyangiitis, microscopic polyangiitis, or anti-GBM disease (Goodpasture's syndrome).

Secondary keratitis or uveitis may occur with scleritis. The most severe complications are associated with necrotizing scleritis.

Vasculitis can be classified by the cause, the location, the type of vessel or the size of vessel.

- "Underlying cause". For example, the cause of syphilitic aortitis is infectious (aortitis simply refers to inflammation of the aorta, which is an artery.) However, the causes of many forms of vasculitis are poorly understood. There is usually an immune component, but the trigger is often not identified. In these cases, the antibody found is sometimes used in classification, as in ANCA-associated vasculitides.

- "Location of the affected vessels". For example, ICD-10 classifies "vasculitis limited to skin" with skin conditions (under "L"), and "necrotizing vasculopathies" (corresponding to systemic vasculitis) with musculoskeletal system and connective tissue conditions (under "M"). Arteritis/phlebitis on their own are classified with circulatory conditions (under "I").

- "Type or size of the blood vessels" that they predominantly affect. Apart from the arteritis/phlebitis distinction mentioned above, vasculitis is often classified by the caliber of the vessel affected. However, there can be some variation in the size of the vessels affected.

According to the size of the vessel affected, vasculitis can be classified into:

- Large vessel: Polymyalgia rheumatica, Takayasu's arteritis, Temporal arteritis

- Medium vessel: Buerger's disease, Kawasaki disease, Polyarteritis nodosa

- Small vessel: Behçet's syndrome, Eosinophilic granulomatosis with polyangiitis, Cutaneous vasculitis, Henoch–Schönlein purpura, Microscopic polyannulomatosis ConditionofSome disorders have vasculitis as their main feature. The major types are given in the table below:

Takayasu's arteritis, polyarteritis nodosa and giant cell arteritis mainly involve arteries and are thus sometimes classed specifically under arteritis.

Furthermore, there are many conditions that have vasculitis as an accompanying or atypical feature, including:

- Rheumatic diseases, such as rheumatoid arthritis, systemic lupus erythematosus, and dermatomyositis

- Cancer, such as lymphomas

- Infections, such as hepatitis C

- Exposure to chemicals and drugs, such as amphetamines, cocaine, and anthrax vaccines which contain the Anthrax Protective Antigen as the primary ingredient.

In pediatric patients varicella inflammation may be followed by vasculitis of intracranial vessels. This condition is called post varicella angiopathy and this may be responsible for arterial ischaemic strokes in children.

Several of these vasculitides are associated with antineutrophil cytoplasmic antibodies. These are:

- Granulomatosis with polyangiitis (formerly known as Wegener's granulomatosis)

- Eosinophilic granulomatosis with polyangiitis (formerly known as Churg-Strauss syndrome)

- Microscopic polyangiitis

Arthralgia is seen in up to half of people, and is usually a non-erosive poly or oligoarthritis primarily of the large joints of the lower extremities.

Inflammatory eye disease can develop early in the disease course and lead to permanent vision loss in 20 percent of cases. Ocular involvement can be in the form of posterior uveitis, anterior uveitis, or retinal vasculitis. Anterior uveitis presents with painful eyes, conjuctival redness, hypopyon, and decreased visual acuity, while posterior uveitis presents with painless decreased visual acuity and visual field floaters. A rare form of ocular (eye) involvement in this syndrome is retinal vasculitis which presents with painless decrease of vision with the possibility of floaters or visual field defects.

Optic nerve involvement in Behçet's disease is rare, typically presenting as progressive optic atrophy and visual loss. However, cases of acute optic neuropathy (specifically anterior ischemic optic neuropathy) have also been reported to occur. Optic nerve atrophy has been identified as the most common cause of visual impairment. Behçet's disease may result in primary or secondary optic nerve involvement. Papilledema as a result of dural sinus thrombosis and atrophy resulting from retinal disease, have been characterized as secondary causes of optic nerve atrophy in Behçet's disease.

Signs and symptoms of acute optic neuropathy include painless loss of vision which may affect either one or both eyes, reduced visual acuity, reduced color vision, relative afferent pupillary defect, central scotoma, swollen optic disc, macular edema, or retrobulbar pain. When these symptoms occur with concurrent mucocutaneous ulcerations, they raise suspicion of acute optic neuropathy in Behçet's Disease. Progressive optic atrophy may result in decreased visual acuity or color vision. Intracranial hypertension with papilledema may be present.

Sarcoidosis can be involved with the joints, bones and muscles. This causes a wide variety of musculoskeletal complaints that act through different mechanisms.

About 5–15% of cases affect the bones, joints, or muscles.

Arthritic syndromes can be categorized in two ways: as acute or chronic.

Sarcoidosis patients suffering acute arthritis often also have bilateral Hilar lymphadenopathy and Erythema nodosum. These three associated syndromes often occur together in Löfgren syndrome. The arthritis symptoms of Löfgren syndrome occur most frequently in the ankles, followed by the knees, wrists, elbows, and metacarpophalangeal joints. Usually true arthritis is not present, but instead, periarthritis appears as a swelling in the soft tissue around the joints that can be seen by ultrasonographic methods.

These joint symptoms tend to precede or occur at the same time as erythema nodosum develops. Even when erythema nodosum is absent, it is believed that the combination of hilar lymphadenopathy and ankle periarthritis can be considered as a variant of Löfgren syndrome.

Enthesitis also occurs in about one-third of patients with acute sarcoid arthritis, mainly affecting the Achilles tendon and heels. Soft tissue swelling of the ankles can be prominent, and biopsy of this soft tissue reveals no granulomas but does show panniculitis that is similar to erythema nodosum.

Chronic sarcoid arthritis usually occurs in the setting of more diffuse organ involvement. The ankles, knees, wrists, elbows, and hands may all be affected in the chronic form and often this presents itself in a polyarticular pattern. Dactylitis similar to that seen in Psoriatic arthritis, that is associated with pain, swelling, overlying skin erythema, and underlying bony changes may also occur. Development of Jaccoud arthropathy (a nonerosive deformity) is very rarely seen.

Bone involvement in sarcoidosis has been reported in 1–13% of cases. The most frequent sites of involvement are the hands and feet, whereas the spine is less commonly affected. Half of the patients with bony lesions experience pain and stiffness, whereas the other half remain asymptomatic.

Periostitis is rarely seen in Sarcoidosis and has been found to present itself at the femoral bone.

Eye involvement occurs in about 10–90% of cases. Manifestations in the eye include uveitis, uveoparotitis, and retinal inflammation, which may result in loss of visual acuity or blindness. The most common ophthalmologic manifestation of sarcoidosis is uveitis. The combination of anterior uveitis, parotitis, VII cranial nerve paralysis and fever is called uveoparotid fever or Heerfordt syndrome (). Development of scleral nodule associated with sarcoidosis has been observed.

Symptoms of episcleritis include mild eye pain, redness, and watery eyes. The pain of episcleritis is typically mild, less severe than in scleritis, and may be tender to palpation.

There are two types of episcleritis: the diffuse type, where the redness involves the entire episclera, and the nodular type, where the redness appears more nodular, involving only a small, well-circumscribed area (sectoral). The diffuse type of episcleritis may be less painful than the nodular type. Sometimes, small nodules are present within the episclera, which move slightly over the sclera with gentle pressure.

Discharge is absent with episcleritis, and vision is unaffected. Patients with episcleritis experience far less photophobia than patients with uveitis. Episcleritis does not cause the presence of cells or flare in the anterior chamber of the eye.

Patients with ARN typically present

- floaters

- redness of the eye

- flashes

- decreased sharpness of vision

- photophobia.

Though uncommon, some patients may experience pain. Most patients will only experience this in one eye (unilateral), though possible for the condition to be seen in both (bilateral, BARN). If the first eye is left without treatment, some cases have shown the disease progressing to the other eye in a month's time. Further progressed stages of the disease can cause blindness in the eye experiencing ARN. Though the disease may be present itself, the inflammation of the retina may not been visualized for decades after the initial signs.

Uveitis may cause pain of the affected eye together with changes in vision. It may be accompanied by nonspecific systemic symptoms such as fever, involuntary weight loss, fatigue, loss of appetite, abdominal pain, and joint pains.

Episcleritis is a benign, self-limiting inflammatory disease affecting part of the eye called the episclera. The episclera is a thin layer of tissue that lies between the conjunctiva and the connective tissue layer that forms the white of the eye (sclera). Episcleritis is a common condition, and is characterized by the abrupt onset of mild eye pain and redness.

There are two types of episcleritis, nodular and simple. Nodular episcleritis lesions have raised surface. Simple episcleritis lesions are flat. There are two subtypes. In diffuse simple episcleritis, inflammation is generalized. In sectoral simple episcleritis, the inflammation is restricted to one region.

Most cases of episcleritis have no identifiable cause, although a small fraction of cases is associated with various systemic diseases. Often people with episcleritis experience it recurrently. Treatment focuses on decreasing discomfort, and includes lubricating eye drops. More severe cases may be treated with topical corticosteroids or oral anti-inflammatory medications (NSAIDs).

The sequence of clinical events in VKH is divided into four phases: prodromal, acute uveitic, convalescent, and chronic recurrent.

The prodromal phase may have no symptoms, or may mimic a non-specific viral infection, marked by flu-like symptoms that typically last for a few days. There may be fever, headache, nausea, meningismus, dysacusia (discomfort caused by loud noises or a distortion in the quality of the sounds being heard), tinnitus, and/or vertigo. Eye symptoms can include orbital pain, photophobia and tearing. The skin and hair may be sensitive to touch. Cranial nerve palsies and optic neuritis are uncommon.

The acute uveitic phase occurs a few days later and typically lasts for several weeks. This phase is heralded by bilateral panuveitis causing blurring of vision. In 70% of VKH, the onset of visual blurring is bilaterally contemporaneous; if initially unilateral, the other eye is involved within several days. The process can include bilateral granulomatous anterior uveitis, variable degree of vitritis, thickening of the posterior choroid with elevation of the peripapillary retinal choroidal layer, optic nerve hyperemia and papillitis, and multiple exudative bullous serous retinal detachments.

The convalescent phase is characterized by gradual tissue depigmentation of skin with vitiligo and poliosis, sometimes with nummular depigmented scars, as well as alopecia and diffuse fundus depigmentation resulting in a classic orange-red discoloration ("sunset glow fundus") and retinal pigment epithelium clumping and/or migration.

The chronic recurrent phase may be marked by repeated bouts of uveitis, but is more commonly a chronic, low-grade, often subclinical, uveitis that may lead to granulomatous anterior inflammation, cataracts, glaucoma and ocular hypertension. Full-blown recurrences are, however, rare after the acute stage is over. Dysacusia may occur in this phase.

The first signs of erythema nodosum are often flu-like symptoms such as a fever, cough, malaise, and aching joints. Some people also experience stiffness or swelling in the joints and weight loss.

Pauci-immune (pauci- Latin: few, little) vasculitis is a form of vasculitis that is associated with minimal evidence of hypersensitivity upon immunofluorescent staining for IgG.

Normally a kidney sample will be subjected to immunofluorescence if rapidly progressive glomerulonephritis is a concern. In this case, the immunofluorescence can show three patterns: linear, granular and negative (pauci-immune). The linear and granular patterns are examples of positive immunofluorescence and are associated with Goodpasture syndrome and post-streptococcal glomerulonephritis accordingly. A negative pattern or pauci-immune pattern can be associated with systemic vasculitis such as microscopic polyangiitis, eosinophilic granulomatosis with polyangiitis (EGPA) or granulomatosis with polyangiitis (GPA). In many cases however, it is limited to the kidney and it is thus called idiopathic.

Since it can be associated with the three systemic vasculitides mentioned above, a pauci-immune pattern finding can be associated with antineutrophil cytoplasmic antibodies (ANCA). Therefore, an ANCA test should follow a negative immunofluorescence result in order to distinguish between the above-mentioned systemic vasculitis.

Peak incidences in 50- to 60-year-olds symptoms include intermittent fever / weight loss / shortness of breath / joint pain.