Department of Medicine, Princess Royal Hospital, Haywards Heath RH16 4EX and Lincoln County Hospital, Greetwell Road, Lincoln LN2 5QY, UK
SIR, Post-streptococcal myalgia is a recognized clinical entity. There have been at least five reported cases [1, 2]. Symptoms usually follow a streptococcal pharyngeal infection and can last up to several weeks [2]. There have been no reported cases of recurrence.
We describe the case of a 20-yr-old woman who presented to her general practitioner with recurrent sore throats. Four weeks later she developed generalized myalgia. Her symptoms got progressively worse to the extent that she could not climb a flight of stairs without feeling tired. She denied joint pains, skin rashes, haematuria, recent urethritis, recreational drug use or sexual contact. She had not travelled abroad recently and denied taking any medication. Clinical examination revealed normal joints and no muscular weakness or tenderness. Her cardiovascular, respiratory and neurological examination was unremarkable.
The patient had normal full blood and differential counts and an erythrocyte sedimentation rate of 2 mm/h. Her routine biochemistry was normal. There was no serological evidence of infection with parvovirus, toxoplasma or cytomegalovirus. EpsteinBarr immunoglobulin (Ig) G antibodies were present but IgM was undetectable in the serum, indicating past infection with the virus. Her Ig levels were normal and she was negative for antinuclear antibodies and rheumatoid factor. Her creatine phosphokinase was 56 IU/l (normal values <200) and C-reactive protein was 6 mg/l (normal <8). The anti-streptolysin O (ASO) titre was elevated at 811 U, and repeat testing after 1 month showed that it had come down to 367 U. The ECG showed a normal PR interval. On the basis of the clinical and laboratory results, she did not fulfil the revised Jones criteria for the diagnosis of acute rheumatic fever.
She was commenced on a 1-month course of phenoxymethyl penicillin at a dose of 250 mg four times a day. Two weeks after commencement of therapy, dramatic symptomatic recovery ensued. She remained asymptomatic and returned to a normal lifestyle 3 weeks later.
A year later, her symptoms recurred, with sore throat preceding myalgia by 4 weeks. Her ASO titre rose from 333 U at the onset of symptoms to 800 U 4 weeks later. Group A streptococcus (GAS) was isolated from a throat swab. Clinical examination and laboratory findings were as before. Her symptoms improved following penicillin at a dose of 250 mg four times a day for 1 month.
Myalgia is a common symptom in clinical practice and has many possible causes. Common causes include infectious diseases, inflammatory rheumatic conditions, endocrine diseases and malignancy. There is a variety of infectious agents that can cause myalgia [1]. Furthermore, antibodies to certain viruses (e.g. coxsackievirus B) and bacteria (e.g. Chlamydia pneumoniae) have been found more frequently in the serum of patients presenting with myalgia [3, 4] than in the general population, but there is no cause-and-effect relationship.
ß-Haemolytic streptococci can cause a wide variety of manifestations, of which arthritis, acute glomerulonephritis and acute rheumatic fever are well recognized [35]. Acute rheumatic fever, as defined by the modified Jones criteria, is rare in the developed world. Other non-suppurative sequelae of streptococcal infections have been reported less frequently. These include pneumonitis, hepatitis and erythema multiforme. High ASO titres have been reported to be associated with a variety of rheumatic syndromes in a series of 76 patients reviewed by Valtonen et al. [6].
It was proposed initially by Harats et al. [1] that myalgia might be a solitary manifestation of post-streptococcal syndrome. The three patients reported in this series had myalgia with serological evidence of recent streptococcal infection. Symptomatic recovery resulted from administration of non-steroidal anti-inflammatory drugs (NSAIDs) or prednisolone. Jansen et al. [2] reported post-streptococcal myalgia that was associated with specific strains of streptococci: GAS M-serotype 100 in one patient and group G streptococcus in another. These two patients were treated with NSAIDs and penicillin, respectively. They had an accompanying systemic inflammatory response. The mean period between acquisition of streptococcal throat infection and the onset of myalgia was 10 days. In our patient, the symptoms of myalgia presented 4 weeks after pharyngitis. This could explain the lack of an inflammatory response. Even though symptoms have been protracted in some of the patients reported so far, recurrence has not been reported. To our knowledge, this is the first reported instance of post-streptococcal myalgia. However, we are unable to say whether the same group and strain of streptococcus was responsible for causing the recurrence, as a throat swab was not performed on our patient's first presentation. Recurrent streptococcal infections are known to trigger active carditis or arthritis in patients with established rheumatic fever [5], and thus recurrent symptoms could reasonably be expected in post-streptococcal myalgia.
Notes
Correspondence to: S. Subramanian, Department of Medicine, Warrington Hospital, Lovely Lane, Warrington WA5 1QG, UK.
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