CREST is not easily diagnosed as it closely mimics symptoms of other connective tissue and autoimmune diseases. Diagnoses are usually given when a patient presents three or more of the five major clinical symptoms. Additionally, blood exams can be given to test for a positive ANAs and ACAs or skin biopsies can be given to help confirm a diagnosis.

CREST syndrome can be noted in up to 10% of patients with primary biliary cirrhosis.

No specific work up is defined. Stenosing tenosynovitis is a clinical diagnosis. However, if rheumatoid arthritis is suspected, laboratory evaluation of is granted (e.g. rheumatoid factor). Imaging studies are not needed to diagnose the condition. However, they can be valuable adjuvants to achieve a diagnosis. An ultrasound or MRI ( the most reliable study) can demonstrate increased thickness of the involved tendons. Thickening and hyper-vascularization of the pulley are the hallmarks of trigger fingers on sonography.

If nasopharyngeal angiofibroma is suspected based on physical examination (a smooth vascular submucosal mass in the posterior nasal cavity of an adolescent male), imaging studies such as CT or MRI should be performed. Biopsy should be avoided as to avoid extensive bleeding since the tumor is composed of blood vessels without a muscular coat.

Antral sign or Holman-Miller sign (forward bowing of posterior wall of maxilla) is pathognomic of angiofibroma.

DSA (digital subtraction angiography) of carotid artery to see the extension of tumors and feeding vessels

Diagnosis of a trigger thumb is solely made by these clinical observations and further classified into four stages:

Infantile digital fibromatosis (also known as an "Inclusion body fibromatosis," "Infantile digital myofibroblastoma," and "Reye tumor") usually occurs as a small, asymptomatic, nodular, dermal fibrous proliferation at the extensor or lateral surface of a finger or toe.

Treatment for Nasopharyngeal angiofibroma (JNA) is primarily surgical. The tumor is primarily excised by external or endoscopic approach. Medical treatment and radiation therapy are only of historical interest.

External approaches:

- transpalatine approach

- transpalatine + sublabial (Sardana's) Approach

- infratemporal Approach

- nasal endoscopic Approach

- transmaxillary Approach

Endoscopic approach is an excellent tool in primary and recurrent JNA, it allows visualisation and precise removal of the lesion. Preoperative embolisation of tumour may be of some use in reducing intraoperative bleeding.

Direct visualization is not common.

A doctor will base his or her diagnosis on the symptoms the patient has and the results of tests, including:

- An X-ray

- Magnetic resonance imaging (MRI), which usually provides the most information

- Computed tomography (CT) scan

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.

Dupuytren’s disease has a high recurrence rate, especially when a person has so called Dupuytren’s diathesis. The term diathesis relates to certain features of Dupuytren's disease and indicates an aggressive course of disease.

The presence of all new Dupuytren’s diathesis factors increases the risk of recurrent Dupuytren’s disease by 71% compared with a baseline risk of 23% in people lacking the factors. In another study the prognostic value of diathesis was evaluated. They concluded that presence of diathesis can predict recurrence and extension. A scoring system was made to evaluate the risk of recurrence and extension evaluating the following values: bilateral hand involvement, little finger surgery, early onset of disease, plantar fibrosis, knuckle pads and radial side involvement.

Minimally invasive therapies may precede higher recurrence rates. Recurrence lacks a consensus definition. Furthermore, different standards and measurements follow from the various definitions.

THS is usually diagnosed via exclusion, and as such a vast amount of laboratory tests are required to rule out other causes of the patient's symptoms. These tests include a complete blood count, thyroid function tests and serum protein electrophoresis. Studies of cerebrospinal fluid may also be beneficial in distinguishing between THS and conditions with similar signs and symptoms.

MRI scans of the brain and orbit with and without contrast, magnetic resonance angiography or digital subtraction angiography and a CT scan of the brain and orbit with and without contrast may all be useful in detecting inflammatory changes in the cavernous sinus, superior orbital fissure and/or orbital apex. Inflammatory change of the orbit on cross sectional imaging in the absence of cranial nerve palsy is described by the more benign and general nomenclature of orbital pseudotumor.

Sometimes a biopsy may need to be obtained to confirm the diagnosis, as it is useful in ruling out a neoplasm.

Differentials to consider when diagnosing THS include craniopharyngioma, migraine and meningioma.

Not much research has been done on the epidemiology of congenital trigger thumbs. There are a few reports on the incidence in their respective studies. The most recent data comes from a Japanese study by Kukichi and Ogino where they found an incidence 3.3 trigger thumbs per 1,000 live births in 1 year old children.

Since elevated PGE2 levels are correlated with PDP, urinary PGE2 can be a useful biomarker for this disease. Additionally, HPGD mutation analyses are relatively cheap and simple and may prove to be useful in early investigation in patients with unexplained clubbing or children presenting PDP-like features. Early positive results can prevent expensive and longtime tests at identifying the pathology.

For the follow-up of PDP disease activity, bone formation markers such as TAP, BAP, BGP, carbodyterminal propeptide of type I procallagen or NTX can play an important role. Other biomarkers that can be considered are IL-6 and receptor activator of NF-κB ligand (RANKL), which are associated with increased bone resorption in some patients. However, further investigation is needed to confirm this use of disease monitoring.

Prostaglandin E2 may also be raised in patients with lung cancer and finger clubbing. This may be related to raised levels of cyclooxygenase-2, an enzyme involved in the metabolism of prostaglandins. A similar association has been noted in cystic fibrosis.

The easiest way to diagnose PDP is when pachydermia, finger clubbing and periostosis of the long bones are present. New bone formation under the periosteum can be detected by radiographs of long bones. In order diagnose PDP, often other diseases must be excluded. For example, to exclude secondary hypertrophic osteoarthropathy, any signs of cardiovascular, pulmonary, hepatic, intestinal and mediastinal diseases must be absent. MRI and ultrasound also have characterictic findings.

Skin biopsy is another way to diagnose PDP. However, it is not a very specific method, because other diseases share the same skin alterations with PDP, such as myxedema and hypothyroidism. In order to exclude these other diseases, hormonal studies are done. For example, thyrotropin and growth hormone levels should be examined to exclude thyroid acropachy and acrome. However, skin biopsy helps to diagnose PDP in patients without skin manifestations.

When clubbing is observed, it is helpful to check whether acroosteolysis of distal phalanges of fingers is present. This is useful to diagnose PDP, because the combination of clubbing and acroosteolysis is only found in PDP and Cheney’s syndrome.

There are a few different classifications conceived to categorize the spectrum of variety of congenital clasped thumb. In literature X classifications have been described for clasped thumb. The two most relevant of the existing classifications, to our opinion, are the classifications of McCarrol and Tjuyuguchi et al.

The most global format is the classification of McCarrol, which divides the congenital clasped thumbs into two groups. Group I includes the supple clasped thumb, when the thumb is only passively correctable. While complex clasped thumbs, thumbs which cannot be moved neither passively or actively, belong to group II.

Tjuyuguchi et al. designed a classification existing of three groups:

- Group I: The supple clasped thumb, where the thumb is passively abductable and extendable against the resistance of thumb flexors, without other digital anomalies.

- Group II: The clasped thumb with hand contractures, where the thumb is not passively extendable and abductable, with or without other digital anomalies.

- Group III: The clasped thumb which is associated with arthrogryposis.

The diagnosis of harlequin-type ichthyosis relies on both physical examination and certain laboratory tests.

Physical assessment at birth is vital for the initial diagnosis of harlequin ichthyosis. Physical examination reveals characteristic symptoms of the condition especially the abnormalities in the skin surface of newborns. Abnormal findings in physical assessments usually result in employing other diagnostic tests to ascertain the diagnosis.

Genetic testing is the most specific diagnostic test for harlequin ichthyosis. This test reveals a loss of function mutation on the ABCA12 gene. This gene is important in the regulation of protein synthesis for the development of the skin layer. Mutations in the gene may cause impaired transport of lipids in the skin layer and may also lead to shrunken versions of the proteins responsible for skin development. Less severe mutations result in a collodion membrane and congenital ichthyosiform erythroderma-like presentation. ABCA12 is an ATP binding cassette (ABC) transporter, and is a member of a large family of proteins that hydrolyze ATP to transport cargo across membranes. ABCA12 is thought to be a lipid transporter in keratinocytes necessary for lipid transport into lamellar granules during the formation of the lipid barrier.

Biopsy of skin may be done to assess the histologic characteristics of the cells. Histological findings usually reveal hyperkeratotic skin cells, which leads to a thick, white and hard skin layer.

If there aren't neurological symptoms (such as difficulties moving, loss of sensation, confusion, etc.) and there is no evidence of pressure on the spinal cord, a conservative approach may be taken such as:

- Drugs, such as aspirin, without steroids to relieve inflammation

- Cervical traction, in which the neck is pulled along its length, thus relieving pressure on the spinal cord

- Using a neck collar or cervical-thoracic suit

If there is pressure on the spinal cord or life-threatening symptoms are present, surgery is recommended.

The natural history of disease for trigger finger remains uncertain.

There is some evidence that idiopathic trigger finger behaves differently in people with diabetes.

Recurrent triggering is unusual after successful injection and rare after successful surgery.

While difficulty extending the proximal interphalangeal joint may persist for months, it benefits from exercises to stretch the finger straighter.

Diagnosis is made almost exclusively by history and physical examination alone. More than one finger may be affected at a time, though it usually affects the index, thumb, middle, or ring finger. The triggering is usually more pronounced late at night and into the morning, or while gripping an object firmly.

If a contracture is less than 30 degrees, it may not interfere with normal functioning. The common treatment is splinting and occupational therapy. Surgery is the last option for most cases as the result may not be satisfactory.

Treatment of THS includes immunosuppressives such as corticosteroids (often prednisolone) or steroid-sparing agents (such as methotrexate or azathioprine).

Radiotherapy has also been proposed.

Treatment is mainly surgical; radiotherapy or chemotherapy is usually an indication of relapse. Head and neck desmoid fibromatosis is a serious condition due to local aggression, specific anatomical patterns and the high rate of relapse. For children surgery is particularly difficult, given the potential for growth disorders.

Treatment includes prompt radical excision with a wide margin and/or radiation. Despite their local infiltrative and aggressive behavior, mortality is minimal to nonexistent for peripheral tumours. In intra-abdominal fibromatosis associated with Familial adenomatous polyposis (FAP), surgery is avoided if possible due to high rates of recurrence within the abdomen carrying significant morbidity and mortality. Conversely, for intra-abdominal fibromatosis without evidence of FAP extensive surgery may still be required for local symptoms, but the risk of recurrence is low.

Treatment of congenital clasped thumb includes two types of therapy: conservative and surgical.

Corticosteroids remain the main treatment modality for IOI. There is usually a dramatic response to this treatment and is often viewed as pathognomonic for this disease. Although response is usually quick, many agree that corticosteroids should be continued on a tapering basis to avoid breakthrough inflammation.

Although many respond to corticosteroid treatment alone, there are several cases in which adjuvant therapy is needed. While many alternatives are available, there is no particular well-established protocol to guide adjuvant therapy. Among the available options there is: surgery, alternative corticosteroid delivery, radiation therapy, non-steroidal anti-inflammatory drugs, cytotoxic agents (chlorambucil, cyclophosphamide), corticosteroid sparing immunosuppressants (methotrexate, cyclosporine, azathioprine), IV immune-globin, plasmapheresis, and biologic treatments (such as TNF-α inhibitors).

Treatment is indicated when the so-called table top test is positive. With this test, the person places their hand on a table. If the hand lies completely flat on the table, the test is considered negative. If the hand cannot be placed completely flat on the table, leaving a space between the table and a part of the hand as big as the diameter of a ballpoint pen, the test is considered positive and surgery or other treatment may be indicated. Additionally, finger joints may become fixed and rigid.

Treatment involves one or more different types of treatment with some hands needing repeated treatment.

The main categories listed by the International Dupuytren Society in order of stage of disease are radiation therapy, needle aponeurotomy (NA), collagenase injection and hand surgery.

Needle aponeurotomy is most effective at "Stage I and Stage II" of 6–90 degrees of deformation. However, it is also used at other stages.

Collagenase injection is most effective at "Stage I" and Stage II" of 6–90 degrees of deformation. However, it is also used at other stages.

Hand surgery is effective at Stage I – Stage IV.