Bornholm disease overview

# Overview
Bornholm disease or epidemic pleurodynia or epidemic myalgia is a disease caused by the Coxsackie B virus or other viruses.The lining around the lungs is called the pleura. Pleurodynia is a general term for pain from this lining, pain in the chest or upper abdomen when the patient breathes. Epidemic pleurodynia is an infection caused by one of several viruses. This type of infection can cause a similar type of pain as the pain that comes from the lining around the lungs. However, in epidemic pleurodynia, the pain comes from the muscles in the chest that join ribs together. Up until 1949, the underlying cause of the disease was undetermined.

# Historical Perspective
In 1872, Daae-Finsen reported an epidemic of "acute muscular rheumatism" occurring in a community called Bamble, giving rise to the name "Bamble disease" in Norway. Subsequent reports, published only in Norwegian, referred to the disease by this name. In 1933, Ejnar Sylvest gave a doctoral thesis describing a Danish outbreak of this disease on Bornholm Island entitled, "Bornholm disease-myalgia epidemica", and this name has persisted. Bornholm disease is named after the Danish island Bornholm where early cases occurred. Some notable outbreaks include those that occurred in Ohio (1936), Oxford (1951), Toronto (1958), and Singapore (1974). It is interesting to note that although the epidemics occurred individual of one another and were disperesed over time and geographical location, the disease pattern and seasonal factors were found to be similar in many cases.

# Pathophysiology
Bornholm disease is a disease caused by one of the group B coxsackie viruses and is less often caused by a group A coxsackie virus or an echovirus, causing pain in the muscles of the chest that join ribs together. The virus is spread by contact and epidemics usually occur during warm weather in temperate regions and at any time in the tropics, primarily through  saliva and feces. From within the pharynx, the viruse multiplies in the throat and intestines, the muscles of the chest wall, abdominal muscles and diaphragm after which it enters the lymphatic tissues. The virus uses autophagy to increase viral replication.

# Causes
Bornholm disease is often due to either the Coxsackie virus or echovirus. The most prevalent strains include Coxsackievirus B, especially B3 and B4, and Coxsackievirus A, including types 4, 6, 9 and 10. Echovirus types 1, 6, 8, 9 and 19 have also been implicated in some cases. Generally, Coxsackievirus B virus is more prevalent in regards to respiratory complaints compared to Coxsackievirus A strains. The clinical spectrum varies depending on age groups for the Coxsackievirus A and B strains of the virus. Although severe progression of the disease is rare, it has been associated in particular with the Coxsackievirus B3 virus.

# Differential Diagnosis
Bornholm Disease has been referred to by various different names, some of which include Devil's Grip, epidemic pleurodynia and epidemic myalgia, to name a few. Apart from the plethora of names presenting possible difficulty in its recognition, it is often a diagnosis that is not part of the initial differential diagnosis' when a patient presents with chest pain. Because of the possibility of life-threatening conditions presenting with similar pain, it often requires extensive workup to exclude other diseases in medical settings. Conditions that should be rules out include Acute Coronary syndromes (ACS), Aortic dissection/ Ruptured aortic aneurysm, Pulmonary embolism, Tension pneumothorax, Pneumonia, Pleurisy/ Pleuritis, Acute appendicitis, Pancreatitis, Cholecystitis, Costochondritis, and Guillain-Barre Syndrome.

# Epidemiology and Demographics
Up to 90% of epidemics occur in the summer and early fall. The illness most commonly strikes people younger than age 30, although older people also may be affected. According to the CDC, strains of the Coxsackie B4 virus were responsible for 1.9% of all enterovirus infections combined, which was equivalent to at least 54 cases in the United States alone. Bornholm disease is seemingly responsible for 20%-40% of all non-cardiac chest pain. Various paediatric studies done at the Chang Gung Memorial Hospital spanning from 2004-2012 found that of a total of 386 cases studied, 158 were due to the Coxsackie A4 virus, 145 were attributable to the Coxsackie B3 virus and only 83 were found to have been due to the Coxsackie B4 virus.

# Screening
According to the U.S. Preventive Service Task Force (USPSTF), there is currently insufficient evidence to screen for Bornholm disease. Viral disease can be supported with physical examinations and laboratory findings.

# Natural History, Complications and Prognosis
Patients experience sudden chest pain that is often described as a sharp, cutting or knife-like sensation as well as a fever that often lasts about 4 to 7 day. Recovery is gradual and may take up-to 10 days with relapses being a common finding but the disease is rarely fatal. Complications are unlikely, but affect children more commonly. These include acute viral meningitis, orchitis, hepatic necrosisand coagulopathy, Pericarditis and disseminated intravascular coagulopathy, amongst others. The prognosis is generally very good, requiring symptomatic treatment for pain and bed rest. In cases including orchitis, suspensory bandages may prove useful.

# History and Symptoms
The most common presenting symptoms include fever, which affects 70% of patients, which may last 4-7 days.The fever may be associated with headaches. Approximately 40% of patients experience severe, acute chest pain that is described as an iron grip around the rib cage and gives rise to the term referred to as 'The Devil's grip'. Poor oral intake, weakness and muscular fatigue are also commonly found. Although patients recover quickly, relapse is common.

# Physical Examination
Physical findings may vary amongst patients and may also vary according to the the underlying cause. If the disease is due to the Coxsackie virus, findings such as oral ulcerations, throat discomfort or pain, diarrhea as well as vomiting may be seen. For patients experiencing localized chest tenderness, abdominal rigidity and guarding may present difficulty performing a complete physical examination. The pain may result in tachycardia. Pulmonary symptoms include pleural effusion, cough, rhinorrhea and difficulty breathing. Fever may present with headaches and potentially progress to febrile seizures.

# Laboratory Tests
In many cases of Bornholm disease, Inflammatory biomarkers such as Erythrocyte sedimentation rate, C-reactive proteinand Creatine Kinase are found to be elevated. Changes in CBC have been found to vary according to the underlying causative strain. Although leukocytosis is a common finding, infection with the A4 strains can result in white cell counts 15000/L. Comparatively, the Coxsackie B3 has been found to cause anemia and thrombocytopenia. Live function testsincluding AST and ALT may be elevated but changes in electrolytes have not been observed. In the event of respiratory or cardiac complications developing, Arterial Blood Gas and Pulse oximetry may be altered.

# Electrocardiogram
Due to the classic cardiac pain, patients presenting with Bornholm disease often have an ECG done to rule out life threatening diseases, such as myocardial infarction. Findings often include non-specific ECG findings may be seen; this includes T wave inversions that often resolve with resolution of the disease and MI can be ruled out due to the absence of ST changes.

# Chest X-Ray
In cases of Bornholm Disease, chest x-ray findings may be visible in the form of pulmonary infiltrates; such findings have been consistent in almost half of all cases. Some uncommon findings include patch consolidationand pleural effusions.

# Other Imaging Findings
Bornholm disease is also referred to as epidemic myalgia. Muscle involvement may be visible on MRI, often as a patchy distribution of thickened fascia and hyper intense muscles.

# Other Diagnostic Studies
Diagnostic findings are limited for Bornholm disease and, because it mimics classic chest pain, extensive testing is often done to rule out cardiac conditions. Other diagnostic studied include stool, blood and throat samples. All of these have been found to contain traces of causative virus strain. In fact, they have also been found in sewage and flies. MRI can reveal changes in the muscle and fascia. Normal nerve conduction studies may be used to differentiate the disease from Guillain-Barre syndrome.

# Medical Treatment
Treatment includes the administration of nonsteroidal anti-inflammatory agents or the application of heat to the affected muscles. In healthy people, pleurodynia is a harmless infection that goes away on its own within a few days. To treat the muscle pain, your doctor probably will recommend over-the-counter pain relievers. If necessary narcotic pain medication can be used. Aspirin should not be given to children with pleurodynia because of the risk of Reye's syndrome, a serious reaction causing brain and liver injury in children who take aspirin during certain viral illnesses.

# Surgery
As the disease is often self-limited and treated medically, surgical interventions are not required. Surgical intervention may be considered in the case of myocarditis if the patient is unresponsive to all other medical treatments and continues to deteriorate.

# Primary Prevention
The goal of Primary prevention is to prevent the occurrence of an illness or a disease before it ever occurs. The viruses that cause epidemic pleurodynia can spread very easily among young children, who tend to put toys or fingers into their mouth. The disease is most likely to spread in day care centers. The best way to prevent infection is to wash hands thoroughly, especially before meals or after changing a diaper or using the bathroom. There is no vaccine to prevent pleurodynia.

# Secondary Prevention
Secondary prevention occurs once the disease has developed and aims to prevent progression and development of further complications. Viral meningitis can be prevented by strict isolation, frequent hand washing and appropriate hand hygiene especially after using the bathroom. The development of orchitis may be prevented by surgical correction of underlying UTI's. Hepatitis is avoidable by the use of vaccines and safe eating habits. Pericarditis can be prevented by the concomitant use of aspirin and colchicine. Respiratory distress can be prevented by controlling various properties, including the tidal volume, PEEP, FiO2, and reducing the risk of aspiration by elevating the head end of bed and maintaining oral hygiene.

# Cost-effectiveness of Therapy
As the treatment is primarily symptomatic and can be controlled with NSAIDs, the treatment is relatively affordable. Because of their low cost, NSAIDs are amongst the most popular and effective drugs in controlling inflammatory induced pain. An average bottle of ibuprofen containing 30 tablets can be purchased for less than $14 in the United Sates.

# Future or Investigational Therapies
The prevention of Bornholm disease focuses on preventing infections with Coxsackie virus, as it is the most common underlying cause. The Coxsackie virus can  persist for prolonged durations. The Coxsackie virus is an RNA virus that is non-enveloped, positive single stranded and has the ability to form an envelope by taking over host membranes which provides resistance. The relationship between Coxsackie viral infections and chronic disease is also of interest, especially autoimmune conditions. These include chronic myocarditis, diabetes and chronic inflammatory myopathy. Apart from studying the relationship between coxsackie virus and chronic conditions, the effects in utero are also being studied. Neonates may present with fetal myocarditis and neurodevelopmental delays, possibly due to meningitis and encephalitis.