Post-streptococcal Arthritis - Clinical Features and Treatment

Introduction:

Post-streptococcal is a rare and not clearly defined clinical syndrome. It is an inflammatory response in the joints or arthritis associated with streptococcal infection. It is said to be not clearly defined because of its conflicting relation with acute rheumatic fever and lack of clear diagnostic criteria and therapeutic recommendations. Unlike acute rheumatic fever, the post-streptococcal infection does not fulfill the Jones criteria for diagnosis.

What Is Post-streptococcal Arthritis?

The term post-streptococcal arthritis is used to denote conditions where the patient suffers from arthritis following a streptococcal pharyngeal infection. Unlike acute rheumatic fever and post-streptococcal arthritis, the complications caused after the infections are unclear. However, post-streptococcal arthritis is characterized by a streptococcal infection of the pharynx, followed by an interval with no symptoms and, thereafter, inflammation of one or more of the joints.

Post-streptococcal arthritis is used to denote the condition where arthritis does not respond to Aspirin (acetylsalicylic acid) or NSAIDs (nonsteroidal anti-inflammatory drugs).

What Are the Clinical Features?

Some of the characteristic features of arthritis include:

• Arthritis of joints.

• Does not respond to medications such as Nonsteroidal anti-inflammatory drugs (NSAIDs) and Aspirin.

• Glomerulonephritis- Inflammation of filters(glomerulus) of the kidney.

• Vasculitis- Inflammation of blood vessels.

• It occurs approximately ten days after an upper respiratory tract infection.

• In most patients, extra-articular symptoms such as cutaneous or cardiac disease.

• Low-grade fever may be present.

• Laboratory results indicate inflammatory markers such as C-reactive protein and erythrocyte sedimentation rate.

• It usually affects children between the ages of eight and fourteen and young adults of the age group of 21 to 27 years.

• Small and large joints of the axial skeleton are usually affected.

• Post-streptococcal arthritis is diagnosed based on a recent streptococcal infection along with arthritis, but the absence of symptoms in Jones criteria. The absence of Jones criteria rules out an acute rheumatic fever.

Musculoskeletal Features:

• It is crucial to distinguish between post-streptococcal arthritis and acute rheumatic fever. It is done by taking a proper medical history of joint symptoms and examining joints.

• Post-streptococcal arthritis has non-migratory acute arthritis that lasts an average of two months, ranging from one week to eight months.

• It does not respond to NSAIDs, unlike acute rheumatic fever.

• Antibiotic prophylaxis does not prevent arthritis; however, it prevents the future risk of infection.

• Tenosynovitis is reported in patients with post-streptococcal arthritis. Tenosynovitis is a painful inflammation of tendons. It can present as nodules in tendons. In the case of acute rheumatic fever, there are subcutaneous nodules, which are painless and found in larger joints.

Carditis:

Although the development of carditis is not clear, it has been reported in 5.8 percent of cases of post-streptococcal arthritis. It can occur without a cardiac murmur. Carditis is the inflammation of the heart. The patient may experience:

• Lightheadedness.

• Dyspnea (shortness of breath) on exertion.

• Palpitations.

• Chest pain.

• Syncope (fainting).

• Dizziness.

• Fatigue.

Clinical Sequelae of Post-streptococcal Arthritis:

• The onset of throat infection: Infection of the throat followed by a symptom-free interval is seen. The incubation period is roughly seven to 10 days.

• Joint involvement: Arthritis or inflammation of joints is seen in large and small joints of the axial skeleton.

• Increased inflammatory markers such as C-reactive protein and erythrocyte sedimentation rate.

• Response to treatment: Post-streptococcal arthritis does not respond to the administration of NSAID.

How to Differentiate Between Post-streptococcal Arthritis and Acute Rheumatic Fever?

It has not been completely established whether post-streptococcal arthritis is an early or mild form of acute rheumatic fever or an entirely different disorder. There are some symptoms that enable a clinician to differentiate between the two and give appropriate treatment.

Some of the differences include:

• Acute rheumatic fever responds to NSAIDs and improves within two days of the start of treatment. Post-streptococcal arthritis does not respond to salicylic acid, unlike the drastic response of acute rheumatic fever.

• Post-streptococcal arthritis has a faster onset; it starts approximately ten days after a streptococcal infection, while acute rheumatic fever takes about 21 days.

• Acute rheumatic fever usually affects large joints.

• Post-streptococcal arthritis usually lasts longer than acute rheumatic fever; P.S.A. usually lasts for about two months.

• Inflammatory markers are lower in post-streptococcal arthritis than in acute rheumatic fever.

• Nodules formed as a result of the disease are found subcutaneously in acute rheumatic fever and are painless, whereas it is found in tendons and is painful in post-streptococcal arthritis.

• Secondary antibiotic prophylaxis is recommended for acute rheumatic fever, while its effectiveness for post-streptococcal infections is not yet established.

What Is an Acute Rheumatic Fever?

Rheumatic fever is a condition that occurs due to a bacterial infection of the throat. Group-A type of Streptococcus is specific to causing acute rheumatic fever. Although Streptococcus is a common cause of throat infection, not all develop rheumatic fever. Acute rheumatic may cause inflammation of the heart (carditis). Symptoms of acute rheumatic fever include arthritis, carditis, skin rashes, and chorea (involuntary movement disorder).

What Is the Jones Criteria?

The differentiation between post-streptococcal infections and acute rheumatic fever is based on Jones criteria. The absence of Jones criteria helps to rule out acute rheumatic fever. The clinical manifestations of acute rheumatic fever have been termed Jones criteria.

The major criteria include:

• Polyarthritis (inflammation of more than one joint).

• Carditis.

• Chorea: involuntary movement disorder.

• Erythema marginatum: reddish rash; it is seen in the early stages of acute rheumatic fever.

• Presence of subcutaneous nodules.

Minor criteria include:

• Arthralgia: Pain in joints. This condition is considered only in the absence of arthritis as there might be different causes of arthralgia.

• Fever.

• Elevation of acute phase reactants.

• Prolonged PR interval in electrocardiogram (ECG).

Acute rheumatic fever is considered if there are two major symptoms present or one major and two minor symptoms.

How to Treat Post-streptococcal Arthritis?

The treatment for post-streptococcal arthritis is conflicting because of the complications that may arise if it recurs. Therefore a patient should be carefully monitored for one year closely.

• Treatment with NSAIDs should be continued until the acute phase of arthritis has been resolved.

• Antibiotics must be administered so as to completely eliminate streptococci from the throat, followed up by secondary antibiotic prophylaxis. It is recommended to administer secondary antibiotic prophylaxis to reduce the possibility of the onset of carditis.

• If a patient develops carditis and if the Jones criteria is met, the diagnosis is made to be acute rheumatic fever and should be treated accordingly.

Conclusion:

Arthritis developing, followed by a streptococcal infection within seven to ten days, is considered to be post-streptococcal arthritis. It is one of the differential diagnoses, along with acute rheumatic fever. Arthritis is present in one or more joints. Although it is a conflicting issue, the lack of response to NSAIDs and certain clinical features differentiate between post-streptococcal arthritis and acute rheumatic fever. Antibiotic administration is the preliminary treatment. Followed by one year of monitoring to check for recurrence.