Definition
Scarlet fever, also known as scarlatina, is a bacterial infection characterized by a distinctive red rash that typically appears in specific individuals infected with group A streptococcus (GAS) bacteria, followed by fever, strep throat, and a “strawberry tongue.” The rash, which feels like sandpaper, is caused by toxins released by the bacteria.
Description
- Here are pointers on how scarlet fever is described and classified:
- Fever and sore throat.
- Bright red sandpaper-like rash, which usually originates on the neck and chest before spreading.
- Pharyngitis.
- Initially white coated, then bright red and bumpy “strawberry tongue”.
Epidemiology
Incidence/Prevalence
- Reported cases. Since 1999, the CDC has documented around 9,400 cases of scarlet fever nationwide.
- While accurate point prevalence data are limited, scarlet fever is considered sporadic in the U.S., with no ongoing endemic activity.
Age
- Scarlet fever primarily impacts children between the ages of 5 and 15. At the same time, it is unusual in those younger than 3 years, mainly because maternal antibodies offer short-lived protection, and their immune systems are not yet fully developed.
Gender
- Generally, there is no gender disparity in scarlet fever between males and females.
Race
- While thorough racial data for scarlet fever specifically are limited, studies on invasive GAS infections (which share the same bacterial origin) propose higher rates among Black and Native American populations, likely tied to socioeconomic factors and healthcare gaps.
Risk factors
- General
- Close contact
- Crowded environments
- Poor hygiene
- Seasonality
- Weakened immunity
- Occupational exposure
- Physiological
- Lack of immunity to streptococcal exotoxins
- Superantigen sensitivity
- Genetic predisposition
- Prior streptococcal infections
Etiology
- Scarlet fever is recognized as a toxin-mediated illness caused by Group A Streptococcus (GAS) bacteria, particularly Streptococcus pyogenes.
- Only specific strains of Streptococcus pyogenes can cause scarlet fever. These strains produce special toxins called streptococcal pyogenic exotoxins (SPEs), that is responsible for systemic symptoms.
- Transmission of bacteria primarily via respiratory droplets from infected persons' sneeze or cough, and is less common through contact with contaminated food or surfaces.
- Pathophysiology
- Primary infection: This process begins with an infection caused by Streptococcus pyogenes, more commonly in the throat (strep throat), but can subsequently arise from skin infections such as impetigo or infected wounds.
- Toxin production and release: Exotoxins act as superantigens, sparking widespread T-cell activation and cytokine secretion.
- Immune reaction: In some individuals, the immune system may mistakenly target the body’s tissues after a streptococcal infection, resulting in non-suppurative complications such as rheumatic fever or post-streptococcal glomerulonephritis.
- Rash development: The rash develops due to toxin-mediated capillary dilation, causing numerous fine erythematous papules, giving a ‘sandpaper’ texture
History
- Seek any onset of sore throat, high fever, and malaise.
- Sought any symptoms of abdominal discomfort or nausea.
- Investigate any exposure to classmates with diagnosed streptococcal pharyngitis.
Physical findings on examination
- The patient may appear moderately ill with fever and tachycardia.
- Facial stimulation with a circumoral pallor around the mouth
- Pharyngeal erythema and exudative tonsillitis.
- Strawberry tongue: White phase: Early coating with bulging red papillae. Red phase: Bright red tongue with distinct papillae.
- Petechiae or erythematous bruising on the soft palate
- Exanthem appears 12–48 hours after fever begins: Begins on the neck and chest, then spreads to trunk and extremities.
- Rash
- Skin peeling begins 1–2 weeks later, especially on palms, soles, and fingertips
General treatment items
- The scarlet fever treatment's focal point is on initiating antibiotic therapy, generally 10 days of oral penicillin V or amoxicillin, or a single intramuscular dose of benzathine penicillin G, to eliminate Group A Streptococcus, alleviate the illness, prevent the spread, and reduce the probability of complications like rheumatic fever.
Surgical Interventions
- Tonsillectomy: May be considered in patients with recurrent streptococcal pharyngitis, airway compromise, not specific to scarlet fever alone.
- Drainage of abscesses: If complications such as peritonsillar abscess, retropharyngeal abscess, or mastoiditis occur, it may be necessary to perform surgical drainage.
Adjunctive Therapies
- Systemic antibiotics and IV hydration may be required in cases with odynophagia.
- Antihistamines are used to alleviate pruritus linked with the peeling rash.
- Emollients help soothe peeling or dry skin during recovery.
- Antipyretic or analgesics are used for relief of throat pain and fever.
Medications indicated with specific doses
Toxoids
Immunoglobulins
Vasodilators
Thrombolytic agents
Dietary or Activity restrictions
- Soft/bland foods: Soups, mashed potatoes, and ice cream can ease throat discomfort.
- Hydration: Drink plenty of fluids, water, broths, and electrolyte solutions to prevent dehydration.
- Avoid irritating food items: Spicy, acidic, or crispy foods such as chips may aggravate a sore throat.
- Rest recommended during fever: Children and adults should rest while feeling unwell.
- Return to school/work: Can resume 24 hours after starting antibiotics and once clear of fever.
- Avoid close contact: Until no longer contagious, avoid sharing utensils and towels.
Disposition
Admission Criteria
- Severe systemic symptoms such as very high fever (>104°F or 40°C) or signs of invasive GAS infection (e.g., sepsis).
- Complications such as Peritonsillar abscess, Retropharyngeal abscess, Otitis media, Pneumonia, Acute glomerulonephritis, Rheumatic fever.
- Unable to take oral antibiotics: Vomiting or severe sore throat, or Dehydration.
- Early age children or susceptible individuals: Infants <1 year with complications.
- Insufficient housing stability or inadequate outpatient care support.
- Immunodeficiency or immunosuppressive therapy.
Discharge criteria
- Afebrile for at least 24 hours.
- Completed at least 24–48 hours of antibiotic therapy.
- Maintaining adequate oral hydration and nutrition.
- No evidence of complications.
- Adequate caregiver education has been provided, and they are confident in continuing care at home.
Monitoring
Symptom progress: monitor for resolution of fever within 24–48 hours after starting antibiotics.
- Rash: should begin to fade within 5–7 days, which may peel afterward.
- Sore throat should improve within 2–3 days.
- General situation: progress in appetite, energy, and comfort level.
- Treatment follow-up: complete the entire 10-day course of antibiotics (e.g, amoxicillin, penicillin V)
- Monitor for side effects or allergic reactions to antibiotics.
Patient Education
- Goals: To assist families in identifying early symptoms and accessing medical care promptly.
- To avoid complications such as rheumatic fever and kidney inflammation.
- To prevent the transmission of infection in homes, schools, and communities.
- General education: To encourage complete recovery and ensure adherence to antibiotic treatment.
- Finish the entire course, typically lasting 10 days, even if your symptoms get better.
- Action Plan for Patients and Families:
- Early diagnosis helps prevent complications.
- Avoid dehydration and prevent transmission.
- Offer educational resources such as those from CDC, AAP, or local health departments.
Complications
- Otitis media (middle ear infection)
- Sinusitis
- Peritonsillar or retropharyngeal abscess
- Cervical lymphadenitis
- Skin infections
- Acute rheumatic fever (ARF)
- Post-streptococcal glomerulonephritis (PSGN)
- Sepsis or streptococcal toxic shock syndrome (STSS)
- Pneumonia
- Septic arthritis or osteomyelitis
- Hair loss and Beau’s lines on nails