From the Guidelines
Scarlatina, strep throat, and measles are distinct infectious diseases with different characteristics, and accurate differentiation is crucial for appropriate treatment and prevention of complications. The key differences between these diseases lie in their causative agents, symptoms, and treatment approaches. Scarlatina (scarlet fever) is caused by group A Streptococcus bacteria and features a sandpaper-like red rash that begins on the neck and chest before spreading, along with a strawberry tongue, high fever, and sore throat. Strep throat, also caused by group A Streptococcus, presents with severe throat pain, swollen tonsils with white patches, fever, and swollen lymph nodes, but typically without a rash. Measles, on the other hand, is caused by a virus and begins with high fever, cough, runny nose, and red eyes, followed by Koplik spots (small white spots) inside the mouth and a characteristic red, blotchy rash that starts on the face and spreads downward, with an incubation period averaging 10-12 days from exposure to prodrome and 14 days from exposure to rash (range: 7-18 days) 1. Some key points to consider when differentiating between these diseases include:
- The presence of a rash and its characteristics
- The presence of respiratory symptoms such as cough and runny nose
- The presence of fever and its severity
- The presence of throat symptoms such as sore throat and swollen tonsils
- The presence of lymph node swelling Treatment differs significantly: both scarlatina and strep throat require antibiotics (typically penicillin or amoxicillin for 10 days), while measles, being viral, requires supportive care only. Measles is preventable through vaccination, while there is no vaccine for streptococcal infections. Prompt diagnosis and appropriate treatment are essential as streptococcal infections can lead to complications like rheumatic fever if untreated, while measles can cause serious complications including pneumonia and encephalitis, with a risk for death from measles or its complications being greater for infants, young children, and adults than for older children and adolescents 1.
From the Research
Differentiation between Scarletina Strep and Measles
The differentiation between Scarletina Strep (Scarlet Fever) and Measles can be made based on the following characteristics:
- Symptoms:
- Causes:
- Transmission:
- Scarlet Fever: spread through close contact with an infected person, usually through respiratory droplets 2.
- Measles: highly contagious, spread through respiratory droplets, and can be transmitted to small, susceptible populations within the United States, mainly through travelers who are infected abroad 3, 4.
- Complications:
- Scarlet Fever: if untreated, can lead to complications such as rheumatic fever and suppurative complications (e.g., cervical lymphadenitis, peritonsillar abscess) 2, 5.
- Measles: complications are relatively common and can be associated with significant morbidity and mortality, especially in pregnant, immunocompromised, or unvaccinated individuals 3, 4.
- Diagnosis and Treatment:
- Scarlet Fever: diagnosis is typically made based on clinical presentation and confirmed by microbiologic testing (e.g., culture, rapid antigen detection test) of a throat swab specimen, and treatment involves antimicrobial therapy with oral penicillin V or amoxicillin 2, 5.
- Measles: diagnosis is confirmed with laboratory testing, which is most commonly a serum immunoglobulin M, and management is mainly supportive, with treatment options including the measles vaccine, intravenous immunoglobulin, vitamin A, and ribavirin for high-risk individuals 3, 4.