The diagnosis of mastoiditis is clinical—based on the medical history and physical examination. Imaging studies provide additional information; The standard method of diagnosis is via MRI scan although a CT scan is a common alternative as it gives a clearer and more useful image to see how close the damage may have gotten to the brain and facial nerves. Planar (2-D) X-rays are not as useful. If there is drainage, it is often sent for culture, although this will often be negative if the patient has begun taking antibiotics. Exploratory surgery is often used as a last resort method of diagnosis to see the mastoid and surrounding areas.

1)positive tuberclin test

2)chest radiograph

3)CT scan

4)cytology/biopsy (FNAC)

5)AFB staining

6)mycobacterial culture

As the symptoms of streptococcal pharyngitis overlap with other conditions, it can be difficult to make the diagnosis clinically. Coughing, nasal discharge, diarrhea, and red, irritated eyes in addition to fever and sore throat are more indicative of a viral sore throat than of strep throat. The presence of marked lymph node enlargement along with sore throat, fever, and tonsillar enlargement may also occur in infectious mononucleosis.

A throat culture is the gold standard for the diagnosis of streptococcal pharyngitis, with a sensitivity of 90–95%. A rapid strep test (also called rapid antigen detection testing or RADT) may also be used. While the rapid strep test is quicker, it has a lower sensitivity (70%) and statistically equal specificity (98%) as a throat culture. In areas of the world where rheumatic fever is uncommon, a negative rapid strep test is sufficient to rule out the disease.

A positive throat culture or RADT in association with symptoms establishes a positive diagnosis in those in which the diagnosis is in doubt. In adults, a negative RADT is sufficient to rule out the diagnosis. However, in children a throat culture is recommended to confirm the result. Asymptomatic individuals should not be routinely tested with a throat culture or RADT because a certain percentage of the population persistently "carries" the streptococcal bacteria in their throat without any harmful results.

If ear infections are treated in a reasonable amount of time, the antibiotics will usually cure the infection and prevent its spread. For this reason, mastoiditis is rare in developed countries. Most ear infections occur in infants as the eustachian tubes are not fully developed and don't drain readily.

In all developed countries with up-to-date modern healthcare the primary treatment for mastoiditis is administration of intravenous antibiotics. Initially, broad-spectrum antibiotics are given, such as ceftriaxone. As culture results become available, treatment can be switched to more specific antibiotics directed at the eradication of the recovered aerobic and anaerobic bacteria. Long-term antibiotics may be necessary to completely eradicate the infection. If the condition does not quickly improve with antibiotics, surgical procedures may be performed (while continuing the medication). The most common procedure is a myringotomy, a small incision in the tympanic membrane (eardrum), or the insertion of a tympanostomy tube into the eardrum. These serve to drain the pus from the middle ear, helping to treat the infection. The tube is extruded spontaneously after a few weeks to months, and the incision heals naturally. If there are complications, or the mastoiditis does not respond to the above treatments, it may be necessary to perform a mastoidectomy: a procedure in which a portion of the bone is removed and the infection drained.

To diagnose this condition, scans or other imaging tests are used. Enlarged nodes in the vicinity of cancer areas could potentially contain cancer.

Probable patients are observed for few weeks until the cause of lymphadenopathy becomes obvious and they are instructed to return to the doctor if there is increase in node size. Biopsy should be performed in case tests suggest malignancy.

The diagnosis usually is made serologically (through complement fixation) and by exclusion of other causes of inguinal lymphadenopathy or genital ulcers. Serologic testing has a sensitivity of 80% after 2 weeks. Serologic testing may not be specific for serotype (has some cross reactivity with other chlamydia species) and can suggest LGV from other forms because of their difference in dilution, 1:64 more likely to be LGV and lower than 1:16 is likely to be other chlamydia forms (emedicine).

For identification of serotypes, culture is often used. Culture is difficult. Requiring a special medium, cycloheximide-treated McCoy or HeLa cells, and yields are still only 30-50%. DFA, or direct fluorescent antibody test, PCR of likely infected areas and pus, are also sometimes used. DFA test for the L-type serovar of C trachomatis is the most sensitive and specific test, but is not readily available.

If polymerase chain reaction (PCR) tests on infected material are positive, subsequent restriction endonuclease pattern analysis of the amplified outer membrane protein A gene can be done to determine the genotype.

Recently a fast realtime PCR (TaqMan analysis) has been developed to diagnose LGV. With this method an accurate diagnosis is feasible within a day. It has been noted that one type of testing may not be thorough enough.

lymphadenopathy is a common biopsy finding, and may often be confused with malignant lymphoma. It may be separated into major morphologic patterns, each with its own differential diagnosis with certain types of lymphoma. Most cases of reactive follicular hyperplasia are easy to diagnose, but some cases may be confused with follicular lymphoma. There are seven distinct patterns of benign lymphadenopathy:

- Follicular hyperplasia: This is the most common type of reactive lymphadenopathy.

- Paracortical hyperplasia/Interfollicular hyperplasia: It is seen in viral infections, skin diseases, and nonspecific reactions.

- Sinus histiocytosis: It is seen in lymph nodes draining limbs, inflammatory lesions, and malignancies.

- Nodal extensive necrosis

- Nodal granulomatous inflammation

- Nodal extensive fibrosis (Connective tissue framework)

- Nodal deposition of interstitial substance

These morphological patterns are never pure. Thus, reactive follicular hyperplasia can have a component of paracortical hyperplasia. However, this distinction is important for the differential diagnosis of the cause.

Incision drainage with proper evacuation of the fluid followed by anti-tubercular medication.

As with all STIs, sex partners of patients who have LGV should be examined and tested for urethral or cervical chlamydial infection. After a positive culture for chlamydia, clinical suspicion should be confirmed with testing to distinguish serotype. Antibiotic treatment should be started if they had sexual contact with the patient during the 30 days preceding onset of symptoms in the patient. Patients with a sexually transmitted disease should be tested for other STDs due to high rates of comorbid infections. Antibiotics are not without risks and prophylaxtic broad antibiotic coverage is not recommended.

"Lymph adenitis" or "lymph node adenitis" is caused by infection in lymph nodes. The infected lymph nodes typically become enlarged, warm and tender. A swelling of lymph nodes due to growth of lymph cells is called lymphadenopathy. Types include:

- Neck

- Cervical adenitis is an inflammation of a lymph node in the neck.

- Tuberculous adenitis (scrofula) is a tuberculous infection of the skin of the neck caused by "Mycobacterium tuberculosis". Non-tuberculous adenitis can also be caused by "Mycobacterium scrofulaceum" or "Mycobacterium avium".

- Abdomen

- Mesenteric adenitis is an inflammation of the mesenteric lymph nodes in the abdomen. It can be caused by the bacterium "Yersinia enterocolitica". If it occurs in the right lower quadrant, it can be mistaken for acute appendicitis, often preceded by a sore throat.

Adenitis is a general term for an inflammation of a gland. Often it is used to refer to lymphadenitis which is the inflammation of a lymph node.

Lymph node enlargement is recognized as a common sign of infectious, autoimmune, or malignant disease. Examples may include:

- Reactive: acute infection ("e.g.," bacterial, or viral), or chronic infections (tuberculous lymphadenitis, cat-scratch disease).

- The most distinctive sign of bubonic plague is extreme swelling of one or more lymph nodes that bulge out of the skin as "buboes." The buboes often become necrotic and may even rupture.

- Infectious mononucleosis is an acute viral infection caused by Epstein-Barr virus and may be characterized by a marked enlargement of the cervical lymph nodes.

- It is also a sign of cutaneous anthrax and Human African trypanosomiasis

- Toxoplasmosis, a parasitic disease, gives a generalized lymphadenopathy ("Piringer-Kuchinka lymphadenopathy").

- Plasma cell variant of Castleman's disease - associated with HHV-8 infection and HIV infection

- Mesenteric lymphadenitis after viral systemic infection (particularly in the GALT in the appendix) can commonly present like appendicitis.

Less common infectious causes of lymphadenopathy may include bacterial infections such as cat scratch disease, tularemia, brucellosis, or prevotella.

- Tumoral:

- Primary: Hodgkin lymphoma and non-Hodgkin lymphoma give lymphadenopathy in all or a few lymph nodes.

- Secondary: metastasis, Virchow's Node, neuroblastoma, and chronic lymphocytic leukemia.

- Autoimmune: systemic lupus erythematosus and rheumatoid arthritis may have a generalized lymphadenopathy.

- Immunocompromised: AIDS. Generalized lymphadenopathy is an early sign of infection with human immunodeficiency virus (HIV), the virus that causes acquired immunodeficiency syndrome (AIDS). "Lymphadenopathy syndrome" has been used to describe the first symptomatic stage of HIV progression, preceding a diagnosis of AIDS.

- Bites from certain venomous snakes such as the pit viper

- Unknown: Kikuchi disease, progressive transformation of germinal centers, sarcoidosis, hyaline-vascular variant of Castleman's disease, Rosai-Dorfman disease, Kawasaki disease, Kimura disease

Lymphangitis is an inflammation or an infection of the lymphatic channels that occurs as a result of infection at a site distal to the channel. The most common cause of lymphangitis in humans is "Streptococcus pyogenes" (Group A strep), although it can also be caused by the fungus "Sporothrix schenckii". Lymphangitis is sometimes mistakenly called "blood poisoning". In reality, "blood poisoning" is synonymous with "sepsis".

Signs and symptoms include a deep reddening of the skin, warmth, lymphadenitis (inflammation of a lymphatic gland), and a raised border around the affected area. The person may also have chills and a high fever along with moderate pain and swelling. A person with lymphangitis should be hospitalized and closely monitored by medical professionals.

Lymphangitis is the inflammation of the lymphatic vessels and channels. This is characterized by certain inflammatory conditions of the skin caused by bacterial infections. Thin red lines may be observed running along the course of the lymphatic vessels in the affected area, accompanied by painful enlargement of the nearby lymph nodes.

When the inferior limbs are affected, the redness of the skin runs over the great saphenous vein location and confusion can be made with a thrombophlebitis.

Chronic lymphangitis is a cutaneous condition that is the result of recurrent bouts of acute bacterial lymphangitis.

PTGC is treated by excisional biopsy and follow-up. It may occasionally recur and in a small proportion of patients has been reported to subsequently develop Hodgkin lymphoma (usually nodular lymphocyte predominant Hodgkin lymphoma).

The differential diagnosis of Kikuchi disease includes systemic lupus erythematosus (SLE), disseminated tuberculosis, lymphoma, sarcoidosis, and viral lymphadenitis. Clinical findings sometimes may include positive results for IgM/IgG/IgA antibodies.

For other causes of lymph node enlargement, see lymphadenopathy.

Diagnosis can be achieved through blood cultures, or cultures of other bodily fluids such as sputum. Bone marrow culture can often yield an earlier diagnosis, but is usually avoided as an initial diagnostic step because of its invasiveness.

Many people will have anemia and neutropenia if bone marrow is involved. MAC bacteria should always be considered in a person with HIV infection presenting with diarrhea.

The diagnosis requires consistent symptoms with two additional signs:

- Chest X-ray or CT scan showing evidence of right middle lobe (or left lingular lobe) lung infection

- Sputum culture or bronchoalveolar lavage culture demonstrating the infection is caused by MAC

Disseminated MAC is most readily diagnosed by one positive blood culture. Blood cultures should be performed in patients with symptoms, signs, or laboratory abnormalities compatible with mycobacterium infection. Blood cultures are not routinely recommended for asymptomatic persons, even for those who have CD4+ T-lymphocyte counts less than 100 cells/uL.

It is important that the patient attend periodic follow-up checks, because even after careful microscopic surgical removal, cholesteatomas may recur. Such recurrence may arise many years, or even decades, after treatment.

A "residual cholesteatoma" may develop if the initial surgery failed to completely remove the original; residual cholesteatomas typically become evident within the first few years after the initial surgery.

A "recurrent cholesteatoma" is a new cholesteatoma that develops when the underlying causes of the initial cholesteatoma are still present. Such causes can include, for example, poor eustachian tube function, which results in retraction of the ear drum, and failure of the normal outward migration of skin.

In a retrospective study of 345 patients with middle ear cholesteatoma operated on by the same surgeon, the overall 5-year recurrence rate was 11.8%. In a different study with a mean follow-up period of 7.3 years, the recurrence rate was 12.3%, with the recurrence rate being higher in children than in adults.

Axillary lymphadenopathy is lymphadenopathy of the axillary lymph nodes.

Cholesteatoma is a persistent disease. Once the diagnosis of cholesteatoma is made in a patient who can tolerate a general anesthetic, the standard treatment is to surgically remove the growth.

The challenge of cholesteatoma surgery is to permanently remove the cholesteatoma whilst retaining or reconstructing the normal functions of the structures housed within the temporal bone.

The general objective of cholesteatoma surgery has two parts. It is both directed against the underlying pathology and directed towards maintaining the normal functions of the temporal bone. These aims are conflicting and this makes cholesteatoma surgery extremely challenging.

Sometimes, the situation results in a clash of surgical aims. The need to fully remove a progressive disease like cholesteatoma is the surgeon's first priority. Preservation of hearing is secondary to this primary aim. If the disease can be removed easily so that there is no increased risk of residual disease, then the ossicles may be preserved. If the disease is difficult to remove, so that there is an increased risk of residual disease, then removal of involved ossicles in order to fully clear cholesteatoma has generally been regarded as necessary and reasonable.

In other words, the aims of cholesteatoma treatment form a hierarchy. The paramount objective is the complete removal of cholesteatoma. The remaining objectives, such as hearing preservation, are subordinate to the need for complete removal of cholesteatoma. This hierarchy of aims has led to the development of a wide range of strategies for the treatment of cholesteatoma.

It is diagnosed by lymph node excision biopsy.

Kikuchi disease is a self-limiting illness which has symptoms which may overlap with Hodgkin's lymphoma leading to misdiagnosis in some patients.

Antinuclear antibodies, antiphospholipid antibodies, anti-dsDNA, and rheumatoid factor are usually negative, and may help in differentiation from systemic lupus erythematosus.

Dermatopathic lymphadenopathy is diagnosed by a lymph node biopsy. It has a characteristic pattern of histomorphology and immunohistochemical staining:

- Paracortical histiocytosis

- Melanin-laden macrophages

- Eosinophils

- Plasma cells (medulla of lymph node)

PTGCs is characterized by:

- follicular hyperplasia (many follicles),

- focally large germinal centres, with poorly demarcated germinal centre (GC)/mantle zone interfaces (as GCs infiltrated by mantle zone lymphocytes), and

- an expanded mantle zone.

Lymph nodes may become enlarged in malignant disease. This cervical lymphadenopathy may be reactive or metastatic. Alternatively, enlarged lymph nodes may represent a primary malignancy of the lymphatic system itself, such as lymphoma (both Hodgkin's and non-Hodgkin's), lymphocytic leukemia,

Metastatic lymph nodes are enlarged because tumor cells have detached from the primary tumor and started growing in the lymph node ("seeded"). Since cancer generally occurs more frequently in older people, this kind of lymphadenopathy is more common in older persons. Metastatic lymph nodes tend to feel hard and may be fixed to underlying tissues and may or may not be tender. Usually the lymph nodes that directly drain the area of the cancer are affected by the spread (e.g. Sometimes metastatic cervical lymph node is detected before the main cancer). In such cases, this discovery leads to a search for the primary malignancy, firstly in the nearby area with endoscopy, "blind" biopsies, and tonsillectomy on the side of the lymphadenopathy. If no tumor is found, then the rest of the body is examined, looking for lung cancer or other possible sites. If still no primary tumor is detected, the term "occult primary" is used.

In lymphoma, usually there are multiple enlarged nodes which feel rubbery to palpation.

- Rhabdomyosarcoma

- Neuroblastoma

MAC in patients with HIV disease is theorized to represent recent acquisition rather than latent infection reactivating (which is the case in many other opportunistic infections in immunocompromised patients).

The risk of MAC is inversely related to the patient's CD4 count, and increases significantly when the CD4 count decreases below 50 cells/mm³. Other risk factors for acquisition of MAC infection include using an indoor swimming pool, consumption of raw or partially cooked fish or shellfish, bronchoscopy and treatment with granulocyte stimulating factor.

Disseminated disease was previously the common presentation prior to the advent of highly active antiretroviral therapy (HAART). Today, in regions where HAART is the standard of care, localized disease presentation is more likely. This generally includes a focal lymphadenopathy/lymphadenitis.