Granulomatous meningoencephalitis (GME) is an inflammatory disease of the central nervous system (CNS) of dogs and, rarely, cats. It is a form of meningoencephalitis. GME is likely second only to encephalitis caused by "canine distemper virus" as the most common cause of inflammatory disease of the canine CNS. The disease is more common in female toy dogs of young and middle age. It has a rapid onset. The lesions of GME exist mainly in the white matter of the cerebrum, brainstem, cerebellum, and spinal cord. The cause is only known to be noninfectious and is considered at this time to be idiopathic. Because lesions resemble those seen in allergic meningoencephalitis, GME is thought to have an immune-mediated cause, but it is also thought that the disease may be based on an abnormal response to an infectious agent. One study searched for viral DNA from "canine herpesvirus", "canine adenovirus", and "canine parvovirus" in brain tissue from dogs with GME, necrotizing meningoencephalitis, and necrotizing leukoencephalitis (see below for the latter two conditions), but failed to find any.

Meningeal syphilis (as known as syphilitic aseptic meningitis or meningeal neurosyphilis) is a chronic form of syphilis infection that affects the central nervous system. Treponema pallidum, which is a spirochate bacterium, is the main cause of syphilis, which spreads drastically throughout the body and can infect all the systems of the body if not treated appropriately. The bacterium is the main cause of the onset of meningeal syphilis and other treponemal diseases, and it consists of a cytoplasmic and outer membrane that can cause a diverse array of diseases in the central nervous system and brain.

Early symptomatic neurosyphillis (or acute syphilitic meningitis or neurorecurrence) is the onset of meningeal syphilis. The symptoms arise as a result of inflamed meninges, which eventually lead up to signs of meningitis.

"Treponema pallidum" invades the nervous system within three to eighteen months after the primary infection. The initial series of events is asymptomatic meningitis, which can remain in the human body system and produce more damage within the body. Every form of neurosyphilis has meningitis as a component; however, every case differs in severity. The individual is infected with syphilis through a gram negative bacteria that only humans can obtain. Syphilis has four stages of infection, which are primary, secondary, latent, and tertiary. If syphilis is not treated, the disease can affect various other systems in the body, including the brain, heart, and vessels. The infection of the heart and vessels leads to meningovascular syphilis, which is usually presented during the secondary stage of syphilis. If syphilis is prolonged, it can affect the nervous system, which is known as neurosyphilis. Meningeal syphilis is a component of neurosyphilis, which usually occurs in the tertiary stage of syphilis.

Arachnoiditis is a chronic disorder with no known cure, and prognosis may be hard to determine because of an unclear correlation between the beginning of the disease and the appearance of symptoms. For many, arachnoiditis is a disabling disease that causes chronic pain and neurological deficits, and may also lead to other spinal cord conditions, such as syringomyelia.

Mumps can be prevented by immunization. Gonococcus, bacteria can be avoided by the use of condoms. Most other causes cannot be prevented.

Acute dacryoadenitis is most commonly due to viral or bacterial infection. Common causes include mumps, Epstein-Barr virus, staphylococcus, and gonococcus.

Chronic dacryoadenitis is usually due to noninfectious inflammatory disorders. Examples include sarcoidosis, thyroid eye disease, and orbital pseudotumor.

Commonly by bacteria – streptococci, spore and non-spore forming anaerobes, etc.

Factors affecting the development of phlegmons are virulence of bacteria and immunity strength.

Systemic features of infection such as increased body temperature (up to 38-40 °C), general fatigue, chills, sweatings, headache, loss of appetite).

Inflammatory signs – dolor (localized pain), calor (increase local tissue temperature), rubor (skin redness/hyperemia), tumor (either clear or non-clear bordered tissue swelling), functio laesa (diminish affected function).

NB: severity of patient condition with phlegmons is directly proportional to the degree of intoxication level i.e. the more severe the condition, the higher the degree of intoxication level.

A noninfectious occurrence of phlegmon can be found in the acute pancreatitis of Systemic Lupus Erythematosus. The immunosuppressive aspects of this disease and the immunosuppressive medications used to treat it blunt each of the signs of infection.

There are many different forms on prevention of syphilis and other sexually transmitted diseases in general. Prevention of syphilis includes avoiding contact of bodily fluids with an infected person. This can be particularly difficult because syphilis is usually transmitted by people who are unaware that they have the disease because they do not have any visible sores or rashes that may denote having an infection in general. Being abstinent or having mutually monogamous sex with a person who is uninfected with any type of sexually transmitted disease is the greatest guarantee of not becoming infected with syphilis or any form of a sexually transmitted disease. Using latex condoms can however reduce the risk of obtaining syphilis. In order to prevent further contamination to other individuals, benzathine penicillin is given to any contacts. Washing, douching, or urinating cannot prevent the transmission of a sexually transmitted disease in general.

Individuals obtain syphilis through a variety of circumstances. In general, syphilis can be transmitted from individual to individual through direct contact with sores that are present on the external genitals, vagina, rectum, anus, lips, or mouth. Transmission can occur through any form of sexual contact, including vaginal, anal, and oral sex. In addition, women who are pregnant and infected with syphilis can transmit the disease onto their child as well. If transmission has occurred, it is important to check up immediately with a physician to avoid further damage.

Cerebrospinal fluid (CSF) analysis shows a large number of white blood cells. Typically small mature lymphocytes are the majority of cells seen, with monocytes and neutrophils making up the rest. Definitive diagnosis is based on histopathology, either a brain biopsy or post-mortem evaluation (necropsy). A CT scan or MRI will show patchy, diffuse, or multifocal lesions. For a number of years, the basic treatment was some type of corticosteroid in combination with one or more immunosuppressive drugs, typically cytosine arabinoside and/or cyclosporine or other medications such as azathioprine, cyclophosphamide, or procarbazine, of which were usually added one at a time to the corticosteroid until a successful combination was found. There is evidence that treatment with radiation therapy for focal GME provides the longest periods of remission.

The disease is classified as either gonococcal urethritis, caused by "Neisseria gonorrhoeae", or non-gonococcal urethritis (NGU), most commonly caused by "Chlamydia trachomatis". NGU, sometimes called nonspecific urethritis (NSU), has both infectious and noninfectious causes.

Urethritis is part of triad of Reiter's Syndrome.

Other causes include:

- Adenoviridae

- Uropathogenic "Escherichia coli" (UPEC)

- Herpes simplex

- Cytomegalovirus

- "Mycoplasma genitalium"

- Reactive arthritis

- "Trichomonas vaginalis"

- "Ureaplasma urealyticum"

- "Methicillin-resistant Staphylococcus aureus"

- "Group B streptococcus"

Tenosynovitis most commonly results from the introduction of bacteria into a sheath through a puncture or laceration wound, though bacteria can also be spread from adjacent tissue or via hematogenous spread. The clinical presentation is therefore as acute infection following trauma. The infection can be mono- or polymicrobial and can vary depending on the nature of the trauma. The most common pathogenic agent is staphylococcus aureus introduced from the skin. Other bacteria linked to infectious tenosynovitis include Pasteurella multocida (associated with animal bites), Eikenella spp. (associated with IV drug use), and Mycobacterium marinum (associated with wounds exposed to fresh or salt water). Additionally, sexually active patients are at risk for hematogenous spread due to Neisseria gonorrhea (see infectious arthritis).

Noninfectious tenosynovitis can arise from overuse or secondary to other systemic inflammatory conditions such as [rheumatoid arthritis] or [reactive arthritis]. If left untreated, the tendons may undergo stenosis, causing conditions such as de Quervain’s and trigger finger.

The root cause of the condition is not entirely clear, and it appears to have multiple causes, including iatrogenic cause from misplaced epidural steroid injection therapy when accidentally administered intrathecally (inside the dura mater, the sac enveloping the arachnoid mater), or from contrast media used in myelography prior to the introduction of Metrizamide. Other noninfectious inflammatory processes include surgery, intrathecal hemorrhage, and the administration of anesthetics (e.g. chloroprocaine), and steroids (e.g. prednisolone, triamcinolone acetonide). A variety of other causes exist, including infectious, inflammatory, and neoplastic processes. Infectious causes include bacterial, viral, fungal, and parasitic agents. Prior spinal surgery has been documented as a cause of "arachnoiditis ossificans", as well as for the adhesive form. It can also be caused by long term pressure from either a severe disc herniation or spinal stenosis.

Tenosynovitis is the inflammation of the fluid-filled sheath (called the synovium) that surrounds a tendon, typically leading to joint pain, swelling, and stiffness. Tenosynovitis can be either infectious or noninfectious. Common clinical manifestations of noninfectious tenosynovitis include de Quervain tendinopathy and stenosing tenosynovitis (more commonly known as trigger finger)

The causes of SIRS are broadly classified as infectious or noninfectious. Causes of SIRS include:

- trauma

- burns

- pancreatitis

- ischemia

- hemorrhage

Other causes include:

- Complications of surgery

- Adrenal insufficiency

- Pulmonary embolism

- Complicated aortic aneurysm

- Cardiac tamponade

- Anaphylaxis

- Drug overdose

Laryngitis that continues for more than three weeks is considered chronic. If laryngeal symptoms last for more than three weeks, a referral should be made for further examination, including direct laryngoscopy. The prognosis for chronic laryngitis varies depending on the cause of the laryngitis.

SIRS is frequently complicated by failure of one or more organs or organ systems. The complications of SIRS include:

- Acute lung injury

- Acute kidney injury

- Shock

- Multiple organ dysfunction syndrome

Approximately 20–35% of people with severe sepsis and 30–70% of people with septic shock die. Lactate is a useful method of determining prognosis with those who have a level greater than 4 mmol/L having a mortality of 40% and those with a level of less than 2 mmol/L have a mortality of less than 15%.

There are a number of prognostic stratification systems such as APACHE II and Mortality in Emergency Department Sepsis. APACHE II factors in the person's age, underlying condition, and various physiologic variables to yield estimates of the risk of dying of severe sepsis. Of the individual covariates, the severity of underlying disease most strongly influences the risk of death. Septic shock is also a strong predictor of short- and long-term mortality. Case-fatality rates are similar for culture-positive and culture-negative severe sepsis. The Mortality in Emergency Department Sepsis (MEDS) score is simpler and useful in the emergency department environment.

Some people may experience severe long-term cognitive decline following an episode of severe sepsis, but the absence of baseline neuropsychological data in most people with sepsis makes the incidence of this difficult to quantify or to study.

With treatment, most types of bacterial pneumonia will stabilize in 3–6 days. It often takes a few weeks before most symptoms resolve. X-ray finding typically clear within four weeks and mortality is low (less than 1%). In the elderly or people with other lung problems, recovery may take more than 12 weeks. In persons requiring hospitalization, mortality may be as high as 10%, and in those requiring intensive care it may reach 30–50%. Pneumonia is the most common hospital-acquired infection that causes death. Before the advent of antibiotics, mortality was typically 30% in those that were hospitalized.

Complications may occur in particular in the elderly and those with underlying health problems. This may include, among others: empyema, lung abscess, bronchiolitis obliterans, acute respiratory distress syndrome, sepsis, and worsening of underlying health problems.

Pneumonia can cause respiratory failure by triggering acute respiratory distress syndrome (ARDS), which results from a combination of infection and inflammatory response. The lungs quickly fill with fluid and become stiff. This stiffness, combined with severe difficulties extracting oxygen due to the alveolar fluid, may require long periods of mechanical ventilation for survival.

Sepsis is a potential complication of pneumonia but occurs usually in people with poor immunity or hyposplenism. The organisms most commonly involved are "Streptococcus pneumoniae", "Haemophilus influenzae", and "Klebsiella pneumoniae". Other causes of the symptoms should be considered such as a myocardial infarction or a pulmonary embolism.

Urethritis is inflammation of the urethra. The most common symptom is painful or difficult urination. It is usually caused by infection with bacteria. The bacterial infection is often sexually transmitted, but not in every instance. Urethritis can be idiopathic.

In common clinical usage, neonatal sepsis refers to a bacterial blood stream infection in the first month of life, such as meningitis, pneumonia, pyelonephritis, or gastroenteritis, but neonatal sepsis also may be due to infection with fungi, viruses, or parasites. Criteria with regard to hemodynamic compromise or respiratory failure are not useful because they present too late for intervention.

Acute laryngitis may persist, but will typically resolve on its own within two weeks. Recovery is likely to be quick if the patient follows the treatment plan. In viral laryngitis, symptoms can persist for an extended amount of time, even when upper respiratory tract inflammation has been resolved.

Idiopathic interstitial pneumonia (IIP), or noninfectious pneumonia are a class of diffuse lung diseases. These diseases typically affect the pulmonary interstitium, although some also have a component affecting the airways (for instance, Cryptogenic organizing pneumonitis). There are seven recognized distinct subtypes of IIP.

Rotavirus, norovirus, adenovirus, and astrovirus are known to cause viral gastroenteritis. Rotavirus is the most common cause of gastroenteritis in children, and produces similar rates in both the developed and developing world. Viruses cause about 70% of episodes of infectious diarrhea in the pediatric age group. Rotavirus is a less common cause in adults due to acquired immunity. Norovirus is the cause in about 18% of all cases.

Norovirus is the leading cause of gastroenteritis among adults in America, causing greater than 90% of outbreaks. These localized epidemics typically occur when groups of people spend time in close physical proximity to each other, such as on cruise ships, in hospitals, or in restaurants. People may remain infectious even after their diarrhea has ended. Norovirus is the cause of about 10% of cases in children.

Viruses (particularly rotavirus) and the bacteria "Escherichia coli" and "Campylobacter" species are the primary causes of gastroenteritis. There are, however, many other infectious agents that can cause this syndrome. Non-infectious causes are seen on occasion, but they are less likely than a viral or bacterial cause. Risk of infection is higher in children due to their lack of immunity and relatively poor hygiene.