Complications of Group A Strep Infection

Group A strep also known as Streptococcus pyogenes is a common gram positive cocci that can cause a wide range of infections in humans. Common infections include a pharyngitis ("strep throat") and skin and soft tissue infections. Here we will review the common presentations of Group A strep infections and their complications. 

Infections Presentations

Infections of the Head and Neck

- Pharyngitis

- Tonsillitis

- Peritonsillar Access 

- Otitis Media

Skin and Soft Tissue Infections

- Erysipelas 

- Cellulitis

- Impetigo

- Necrotizing Fasciitis

- Perianal streptococcal dermatitis

Non-Infections Presentations

One of the virulence factors of Streptococcus pyogenes is through toxins. The three main toxins that strep pyogenes produces are: 1) Erythrogenic exotoxin A 2) Streptolysin O and 3) Streptococcal pyrogenic exototoxins

Toxin-mediated diseases

- Scarlet Fever

    - The erythrogenic exotoxin A, B or C produced by strep pyogenes can be transmitted via aerosols and cause a delayed-type skin reaction. The clinical features of scarlet fever include a scarlet-coloured maculopapular rash which is fine, erythematous and sandpaper-like in texture, flushed cheeks, perioral pallor, strawberry tongue. 7-10 after resolution of rash desquamation of skin in flakes may occur. 

- Streptococcal toxic shock-like syndrome

    -While toxic shock syndrome is caused by Staph aureus, strep pyogenes can also produce a toxic shock-like syndrome which is caused by release of its pyrogenic exotoxin. Clinical features include: Fever, flu-like symptoms, transient erythematous macular rash, strawberry tongue, conjunctivitis, and symptoms of shock if severe. 

Immunologic Complications 

- Acute Rheumatic Fever 

    - Acute rheumatic fever (ARF) is an inflammatory sequela involving the heart (pancarditis), joints (migratory polyarthritis), skin (subcutaneous nodules and erythema migrans) and CNS (Sydenham Chorea) that occurs two to four weeks after an untreated infection with GAS infection

- Poststreptococcal Glomerulonephritis

    -An acute glomerular inflammation that results from a preceding infection with nephritogenic strains of group A (beta-hemolytic) Streptococcus pyogenes. Most commonly seen in children approximately 10–30 days following group A streptococcal tonsillopharyngitis or possibly skin infections such as impetigo.

- Acute Post-streptococcal polymyalgia

Acute Post-streptococcal polymyalgia is a rare immunological phenomenon of a GAS infection. Common features include sudden onset of muscular pain with fever usually after an acute upper respiratory tract infection. 

References: 

Rosenthal KS, Tan MJ. Rapid Review Microbiology and Immunology, 3rd Edition. Elsevier; 2010

Venuta A, Ferrari P, Beverelli A, Bettelli F, Laudizi L. Acute post-streptococcal polymyalgia: two new cases with a review of the literature. Eur J Pediatr. 1995 Jun;154(6):475-6. doi: 10.1007/BF02029359. PMID: 7671947.

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