A detailed history is important to elicit any recent medications, any risk of hepatitis infection, or any recent diagnosis with a connective tissue disorder such as systemic lupus erythematosus (SLE). A thorough physical exam is needed as usual.

- Lab tests. Basic lab tests may include a CBC, chem-7 (look for creatinine), muscle enzyme, liver function tests, ESR, hepatitis seroloties, urinalysis, CXR, and EKG. Additional, more specific tests include:

- Antinuclear antibody (ANA) test can detect an underlying connective tissue disorder, especially SLE

- Complement levels that are low can suggest mixed cryoglobulinemia, hepatitis C infection, and SLE, but not most other vasculitides.

- Antineutrophil cytoplasmic antibody (ANCA) may highly suggest granulomatosis with polyangiitis, microscopic polyangiitis, eosinophilic granulomatosis with polyangiitis, or drug-induced vasculitis, but is not diagnostic.

- Electromyography. It is useful if a systemic vasculitis is suspected and neuromuscular symptoms are present.

- Arteriography. Arteriograms are helpful in vasculitis affecting the large and medium vessels but not helpful in small vessel vasculitis. Angiograms of mesenteri or renal arteries in polyarteritis nodosa may show aneurysms, occlusions, and vascular wall abnormalities. Arteriography are not diagnostic in itself if other accessible areas for biopsy are present. However, in Takayasu's arteritis, where the aorta may be involved, it is unlikely a biopsy will be successful and angiography can be diagnostic.

- Tissue biopsy. This is the gold standard of diagnosis when biopsy is taken from the most involved area.

Diagnosis of arteritis is based on unusual medical symptoms. Similar symptoms may be caused by a number of other conditions, such as Ehlers-Danlos syndrome and Marfan syndrome (both heritable disorders of connective tissue), tuberculosis, syphilis, spondyloarthropathies, Cogans’ syndrome, Buerger's, Behcet's, and Kawasaki disease. Various imaging techniques may be used to diagnose and monitor disease progression. Imaging modalities may include direct angiography, magnetic resonance angiography, and ultrasonography.

Angiography is commonly used in the diagnosis of Takayasu arteritis, especially in the advanced stages of the disease, when arterial stenosis, occlusion, and aneurysms may be observed. However, angiography is a relatively invasive investigation, exposing patients to large doses of radiation, so is not recommended for routine, long-term monitoring of disease progression in patients with Takayasu arteritis.

Computed tomography angiography can determine the size of the aorta and its surrounding branches, and can identify vessel wall lesions in middle to late stages of arteritis. CTA can also show the blood flow within the blood vessels. Like angiography, CTA exposes patients to high dosages of radiation.

Magnetic resonance angiography is used to diagnose Takayasu arteritis in the early stages, showing changes such as the thickening of the vessel wall. Even small changes may be measured, making MRA a useful tool for monitoring disease progression without exposing patients to the radiation of direct angiography or CTA. MRA is an expensive investigation, and shows calcification of the aorta and distal branches less clearly than other imaging methods.

Ultrasonography is an ideal method of diagnosing patients in early stages of arteritis when inflammation in the vessel walls occurs. It can also show the blood flow within the blood vessels. Ultrasonography is a popular first-line investigation for diagnosis because it is relatively quick, cheap, noninvasive, and does not expose patients to radiation. It is also used for long-term monitoring of disease progression in Takayasu arteritis. Not all vascular lesions are visible on ultrasound, and the accuracy of the scan depends, to some extent, on the person reading the scan, as the results are observed in real time.

The first-line treatment for arteritis is oral glucocorticoid (steroid) medication, such as prednisone, taken daily for a period of three months. After this initial phase, the medication may be reduced in dose or frequency, e.g. every other day, if possible. If the disease worsens with the new treatment schedule, a cytotoxic medication may be given, in addition to the glucocorticoid. Commonly used cytotoxic agents include azathioprine, methotrexate, or cyclophosphamide. The dose of glucocorticoid medication may be decreased if response to treatment is good. This medication may be reduced gradually once the disease becomes inactive, slowly tapering the dose (to allow the body time to adjust) until the medication may be stopped completely. Conversely, if the disease remains active, the medication will need to be increased. After six months, if the medication cannot be reduced in frequency to alternate days, or if in 12 months the medications cannot be stopped completely, then treatment is deemed to have failed.

Pulsed therapy is an alternative method of administering the medications above, using much higher doses over a short period of time (a pulse), to reduce the inflammation within the arteries. Methylprednisolone, a glucocorticoid, is often used for pulse therapy; cyclophosphamide is an alternative. This method has been shown to be successful for some patients. Immunosuppressive pulse therapy, such as with cyclophosphamide, has also demonstrated relief of symptoms associated with arteritis.

Abdominal ultrasound will typically be normal. Liver function tests will typically be normal or unchanged from baseline as the infection does not involve the liver parenchyma. If a D-dimer is ordered, which it often is when there is pleuritic torso pain, it will usually be markedly elevated but other testing for pulmonary embolism will be normal. CT of the abdomen with IV contrast may show subtle enhancement of the liver capsule, but this may be missed by radiologists if they are not advised to look for it. Testing for gonorrhea and chlamydia should be performed to make the diagnosis. An endocervical or low vaginal swab should be taken to test for these organisms. Antibody testing is rarely required but may be considered if other tests are non-diagnostic and suspicion is high.

Laparoscopy is also rarely required, but may be performed when the diagnosis is uncertain and may reveal "violin string" adhesions of parietal peritoneum to liver.

De Quervain syndrome is diagnosed clinically, based on history and physical examination, though diagnostic imaging such as x-ray may be used to rule out fracture, arthritis, or other causes, based on the patient's history and presentation. Finkelstein's test is a physical exam maneuver used to diagnose de Quervain syndrome. To perform the test, the examiner grasps the thumb and sharply deviates the hand toward the ulnar side. If sharp pain occurs along the distal radius (top of forearm, about an inch below the wrist), de Quervain's syndrome is likely. While a positive Finkelstein's test is often considered pathognomonic for de Quervain syndrome, the maneuver can also cause pain in those with osteoarthritis at the base of the thumb.

Differential diagnoses include:

1. Osteoarthritis of the first carpo-metacarpal joint

2. Intersection syndrome—pain will be more towards the middle of the back of the forearm and about 2–3 inches below the wrist

3. Wartenberg's syndrome

There is no specific pathological testing or technique available for the diagnosis of the disease, although the International Study Group criteria for the disease are highly sensitive and specific, involving clinical criteria and a pathergy test. Behçet's disease has a high degree of resemblance to diseases that cause mucocutaneous lesions such as "Herpes simplex" labialis, and therefore clinical suspicion should be maintained until all the common causes of oral lesions are ruled out from the differential diagnosis.

Visual acuity, or color vision loss with concurrent mucocutaneous lesions or systemic Behçet's disease symptoms should raise suspicion of optic nerve involvement in Behçet's disease and prompt a work-up for Behçet's disease if not previously diagnosed in addition to an ocular work-up. Diagnosis of Behçet's disease is based on clinical findings including oral and genital ulcers, skin lesions such as erythema nodosum, acne, or folliculitis, ocular inflammatory findings and a pathergy reaction. Inflammatory markers such ESR, and CRP may be elevated. A complete ophthalmic examination may include a slit lamp examination, optical coherence tomography to detect nerve loss, visual field examinations, fundoscopic examination to assess optic disc atrophy and retinal disease, fundoscopic angiography, and visual evoked potentials, which may demonstrate increased latency. Optic nerve enhancement may be identified on Magnetic Resonance Imaging (MRI) in some patients with acute optic neuropathy. However, a normal study does not rule out optic neuropathy. Cerebrospinal fluid (CSF) analysis may demonstrate elevated protein level with or without pleocytosis. Imaging including angiography may be indicated to identify dural venous sinus thrombosis as a cause of intracranial hypertension and optic atrophy.

In this table: ANA = Antinuclear antibodies, CRP = C-reactive protein, ESR = Erythrocyte Sedimentation Rate, "ds"DNA = double-stranded DNA, ENA = extractable nuclear antigens, RNP = ribonucleoproteins; VDRL = Venereal Disease Research Laboratory

Diagnosis can be established using plain film x-rays as well as CT scan of the neck/cervical spine. Children with Down's syndrome have inherently lax ligaments making them susceptible to this condition. In select cases, these children may require pre-operative imaging to assess the risk for complications after procedures such as adenoidectomy.

Those affected with deficiency of the interleukin-1–receptor antagonist can have diagnosis achieved via noting an increase of erythrocyte sedimentation rate, as well as the following:

- Genetic test

- Radiological findings

- Clinical findings

According to the International Study Group guidelines, for a patient to be diagnosed with Behçet's disease, the patient must have oral (aphthous) ulcers (any shape, size, or number at least 3 times in any 12 months period) along with 2 out of the following 4 "hallmark" symptoms:

- eye inflammation (iritis, uveitis, retinal vasculitis, cells in the vitreous)

- genital ulcers (including anal ulcers and spots in the genital region and swollen testicles or epididymitis in men)

- pathergy reaction (papule >2 mm dia. 24–48 hrs or more after needle-prick). The pathergy test has a specificity of 95 percent to 100 percent, but the results are often negative in American and European patients

- skin lesions (papulo-pustules, folliculitis, erythema nodosum, acne in post-adolescents not on corticosteroids)

Despite the inclusive criteria set forth by the International Study Group, there are cases where not all the criteria can be met and therefore a diagnosis cannot readily be made. There is however a set of clinical findings that a physician can rely upon in making a tentative diagnosis of the disease; essentially Behçet's disease does not always follow the International Study Group guidelines and so a high degree of suspicion for a patient who presents having any number of the following findings is necessary:

- arthritis/arthralgia

- cardio-vascular problems of an inflammatory origin

- changes of , psychoses

- deep vein thrombosis

- epididymitis

- extreme exhaustion

- inflammatory problems in chest and lungs

- mouth ulcers

- nervous system symptoms

- problems with hearing or balance

- stomach or bowel inflammation

- superficial thrombophlebitis

- any other members of the family with a diagnosis of Behçet's disease.

The French Vasculitis Study Group has developed a five-point system ("five-factor score") that predicts the risk of death in Churg–Strauss syndrome using clinical presentations. These factors are:

- Reduced renal function (creatinine >1.58 mg/dl or 140 µmol/l)

- Proteinuria (>1 g/24h)

- Gastrointestinal hemorrhage, infarction, or pancreatitis

- Involvement of the central nervous system

- Cardiomyopathy

The lack of any of these factors indicates milder case, with a five-year mortality rate of 11.9%. The presence of one factor indicates severe disease, with a five-year mortality rate of 26%, and two or more indicate very severe disease: 46% five-year mortality rate.

The best imaging modality for idiopathic orbital inflammatory disease is contrast-enhanced thin section magnetic resonance with fat suppression. The best diagnostic clue is a poorly marginated, mass-like enhancing soft tissue involving any area of the orbit.

Overall, radiographic features for idiopathic orbital inflammatory syndrome vary widely. They include inflammation of the extraocular muscles (myositis) with tendinous involvement, orbital fat stranding, lacrimal gland inflammation and enlargement (dacryoadenitis), involvement of the optic sheath complex, uvea, and sclera, a focal intraorbital mass or even diffuse orbital involvement. Bone destruction and intracranial extension is rare, but has been reported. Depending on the area of involvement, IOI may be categorized as:

- Myositic

- Lacrimal

- Anterior – Involvement of the globe, retrobulbar orbit

- Diffuse – Multifocal intraconal involvement with or without an extraconal component

- Apical – Involving the orbital apex and with intracranial involvement

Tolosa–Hunt syndrome is a variant of orbital pseudotumor in which there is extension into the cavernous sinus through the superior orbital fissure. Another disease variant is Sclerosing pseudotumor, which more often presents bilaterally and may extend into the sinuses.

CT findings

In non-enhanced CT one may observe a lacrimal, extra-ocular muscle, or other orbital mass. It may be focal or infiltrative and will have poorly circumscribed soft tissue. In contrast-enhanced CT there is moderate diffuse irregularity and enhancement of the involved structures. A dynamic CT will show an attenuation increase in the late phase, contrary to lymphoma where there is an attenuation decrease. Bone CT will rarely show bone remodeling or erosion, as mentioned above.

MR findings

On MR examination there is hypointensity in T1 weighted imaging (WI), particularly in sclerosing disease. T1WI with contrast will show moderate to marked diffuse irregularity and enhancement of involved structures. T2 weighted imaging with fat suppression will show iso- or slight hyperintensity compared to muscle. There is also decreased signal intensity compared to most orbital lesions due to cellular infiltrate and fibrosis. In chronic disease or sclerosing variant, T2WI with FS will show hypointensity (due to fibrosis). Findings on STIR (Short T1 Inversion Recovery) are similar to those on T2WI FS. In Tolosa–Hunt syndrome, findings include enhancement and fullness of the anterior cavernous sinus and superior orbital fissure in T1WI with contrast, while MRA may show narrowing of cavernous sinus internal carotid artery (ICA).

Ultrasonographic findings

On grayscale ultrasound there is reduced reflectivity, regular internal echoes, and weak attenuation, in a way, similar to lymphoproliferative lesions.

Treatment is targeted to the underlying cause. However, most vasculitis in general are treated with steroids (e.g. methylprednisolone) because the underlying cause of the vasculitis is due to hyperactive immunological damage. Immunosuppressants such as cyclophosphamide and azathioprine may also be given.

A systematic review of antineutrophil cytoplasmic antibody (ANCA) positive vasculitis identified best treatments depending on whether the goal is to induce remission or maintenance and depending on severity of the vasculitis.

The cause of Felty's syndrome is unknown, but it has been found to be more common in those with chronic rheumatoid arthritis. Some patients have Human Leukocytic Antigen (HLA-DR4) in their serum. This syndrome is mostly present in people having extra articular manifestations of rheumatoid arthritis. People with this syndrome are at risk of infection because they have a low white blood cell count.

RA in patients with Felty's syndrome is chronic (after 10-15 years), and presents with increased severity along with extra articular manifestations. RA can be mistaken for other conditions such as gout if not clinically diagnosed. Diagnosis can be confirmed by use of X-rays or synovial fluid analysis.

Diagnostic markers include eosinophil granulocytes and granulomas in affected tissue, and antineutrophil cytoplasmic antibodies (ANCA) against neutrophil granulocytes. The American College of Rheumatology 1990 criteria for diagnosis of Churg–Strauss syndrome lists these criteria:

- Asthma

- Eosinophilia, i.e. eosinophil blood count greater than 500/microliter, or hypereosinophilia, i.e. eosinophil blood count greater than 1,500/microliter

- Presence of mononeuropathy or polyneuropathy

- Unfixed pulmonary infiltrates

- Presence of paranasal sinus abnormalities

- Histological evidence of extravascular eosinophils

For classification purposes, a patient shall be said to have Churg–Strauss syndrome (CSS) if at least four of these six criteria are positive. The presence of any four or more of the six criteria yields a sensitivity of 85% and a specificity of 99.7%.

Treatment includes anti-inflammatory medications and immobilization of the neck in addition to treatment of the offending infectious cause (if any) with appropriate antibiotics. Early treatment is crucial to prevent long-term sequelae. Surgical fusion may be required for residual instability of the joint.

Trochleitis is diagnosed based on three criteria: 1) demonstration of inflammation of superior oblique tendon/ trochlea region, 2) periorbital pain and tenderness to palpation in the area of the sore trochlea, and 3) worsening of pain on attempted vertical eye movement, particularly with adduction of the eye. It is important to identify trochleitis because it is a treatable condition and the patient can benefit much from pain relief. Treatment consists of a single injection of corticosteroids to the affected peritrochlear region. A specific "cocktail" consisting of 0.5 ml of depomedrol (80 mg/ml) and 0.5 ml of 2% lidocaine can be injected into the trochlea; immediate relief due to the effects of the local anesthetic indicates successful placement. However, great care must be taken as the injection is in the region of several arteries, veins and nerves. The needle should not be too small (so as not to penetrate tiny structures), the surgeon should draw back on the syringe (to ensure not have pierced a vessel), the lidocaine should not contain epinephrine (which could cause vasospasm), and the pressure of the injection must always be controlled. Only a limited number of injections can be made as they would otherwise lead to muscle atrophy. Diagnosis can be confirmed by response to this treatment; pain and swelling are expected to disappear in 48–72 hours. Some patients experience recurrence of trochleitis.

As with many musculoskeletal conditions, the management of de Quervain's disease is determined more by convention than scientific data. From the original description of the illness in 1895 until the first description of corticosteroid injection by Jarrod Ismond in 1955, it appears that the only treatment offered was surgery. Since approximately 1972, the prevailing opinion has been that of McKenzie (1972) who suggested that corticosteroid injection was the first line of treatment and surgery should be reserved for unsuccessful injections. A systematic review and meta-analysis published in 2013 found that corticosteroid injection seems to be an effective form of conservative management of de Quervain's syndrome in approximately 50% of patients, although more research is needed regarding the extent of any clinical benefits. Efficacy data are relatively sparse and it is not clear whether benefits affect the overall natural history of the illness.

Most tendinoses are self-limiting and the same is likely to be true of de Quervain's although further study is needed.

Palliative treatments include a splint that immobilized the wrist and the thumb to the interphalangeal joint and anti-inflammatory medication or acetaminophen. Systematic review and meta-analysis do not support the use of splinting over steroid injections.

Surgery (in which the sheath of the first dorsal compartment is opened longitudinally) is documented to provide relief in most patients. The most important risk is to the radial sensory nerve.

Some occupational and physical therapists suggest alternative lifting mechanics based on the theory that the condition is due to repetitive use of the thumbs during lifting. Physical/Occupational therapy can suggest activities to avoid based on the theory that certain activities might exacerbate one's condition, as well as instruct on strengthening exercises based on the theory that this will contribute to better form and use of other muscle groups, which might limit irritation of the tendons.

Some occupational and physical therapists use other treatments, in conjunction with Therapeutic Exercises, based on the rationale that they reduce inflammation and pain and promote healing: UST, SWD, or other deep heat treatments, as well as TENS, acupuncture, or infrared light therapy, and cold laser treatments. However, the pathology of the condition is not inflammatory changes to the synovial sheath and inflammation is secondary to the condition from friction. Teaching patients to reduce their secondary inflammation does not treat the underlying condition but may reduce their pain; which is helpful when trying to perform the prescribed exercise interventions.

Getting Physical Therapy before surgery or injections has been shown to reduce overall costs to patients and is a viable option to treat a wide array of musculoskeletal injuries.

Still's disease does not affect children under 6 months old.

Hyperimmunoglobulin D syndrome in 50% of cases is associated with mevalonate kinase deficiency which can be measured in the leukocytes.

The diagnosis is based on observing the patient and finding the constellation of symptoms and signs described above. A few blood tests help, by showing signs of long standing inflammation. There is no specific test for the disease, though now that the gene that causes the disease is known, that may change.

Routine laboratory investigations are non specific: anaemia, increased numbers of polymorphs, an elevated erythrocyte sedimentation rate and elevated concentrations of C-reactive protein are typically all the abnormalities found. Lumbar puncture shows elevated levels of polymorphs (20-70% of cases) and occasionally raised eosinophil counts (0-30% of cases). CSF neopterin may be elevated.

The X ray changes are unique and charactistic of this syndrome. These changes include bony overgrowth due to premature ossification of the patella and the long bone epiphyses in very young children and bowing of long bones with widening and shortening periosteal reaction in older ones.

Audiometry shows a progressive sensineural deafness. Visual examination shows optic atrophy and an increase in the blind spot. CT is usually normal but may show enlargement of the ventricles. MRI with contrast may show enhancement of leptomeninges and cochlea consistent with chronic meningitis. EEG shows is non specific with slow waves and spike discharges.

Polymorphs tend to show increased expression of CD10.

Treatment involves a course of antibiotics to cover the appropriate organisms, typically ceftriaxone plus azithromycin. Laparoscopy for lysis of adhesions may be performed for refractory pain.

A thorough medical history and physical examination, including a neurological examination, are the first steps in making a diagnosis. This alone may be sufficient to diagnose Bell's Palsy, in the absence of other findings. Additional investigations may be pursued, including blood tests such as ESR for inflammation, and blood sugar levels for diabetes. If other specific causes, such as sarcoidosis or Lyme disease are suspected, specific tests such as angiotensin converting enzyme levels, chest x-ray or Lyme titer may be pursued. If there is a history of trauma, or a tumour is suspected, a CT scan may be used.

Costochondritis is a common condition and is responsible for 30% of emergency room chest pain related visits. One-fifth of visits to the primary care physician are for musculoskeletal chest pain; of this 20% of primary care office visits, 13% is due to costochondritis. Costochondritis cases are most often seen in people older than age 40 and occurs more often in women.

Treatments are generally directed toward stopping the inflammation and suppressing the immune system. Typically, corticosteroids such as prednisone are used. Additionally, other immune suppression drugs, such as cyclophosphamide and others, are considered. In case of an infection, antimicrobial agents including cephalexin may be prescribed. Affected organs (such as the heart or lungs) may require specific medical treatment intended to improve their function during the active phase of the disease.