Editing Scarlet fever (section)

==Signs and symptoms==
Scarlet fever typically presents with a sudden onset of [[sore throat]], fever, and [[malaise]]. Headache, nausea, vomiting and [[abdominal pain]] may also be present.<ref name="Wessels2">{{cite journal |last1=Wessels |first1=Michael R. |title=Pharyngitis and Scarlet Fever |url=https://www.ncbi.nlm.nih.gov/books/NBK333418/#pharyngitis.Clinical_features |website=Streptococcus pyogenes: Basic Biology to Clinical Manifestations |publisher=University of Oklahoma Health Sciences Center |access-date=22 December 2022 |date=2016 |pmid=26866221 |archive-date=3 March 2021 |archive-url=https://web.archive.org/web/20210303033712/https://www.ncbi.nlm.nih.gov/books/NBK333418/#pharyngitis.Clinical_features |url-status=live }}</ref> Scarlet fever usually follows from a [[group A streptococcal infection]] that involves a ''strep throat'', such as [[tonsillitis|streptococcal tonsillitis]] or more usually [[streptococcal pharyngitis]]. Often these can present together, known as ''pharyngotonsillitis''. The signs and symptoms are therefore those of a ''strep throat'' but these are followed by the inclusion of the characteristic [[exanthem|widespread rash]].<ref name=Andrew2020>{{cite book |last1=James |first1=William D. |last2=Elston |first2=Dirk |last3=Treat |first3=James R. |last4=Rosenbach |first4=Misha A. |last5=Neuhaus |first5=Isaac |title=Andrews' Diseases of the Skin: Clinical Dermatology |date=2020 |publisher=Elsevier |location=Edinburgh |isbn=978-0-323-54753-6 |page=259-260 |edition=13th |chapter-url=https://books.google.com/books?id=UEaEDwAAQBAJ&pg=PA259 |language=en |chapter=14. Bacterial infections |access-date=30 January 2023 |archive-date=16 May 2023 |archive-url=https://web.archive.org/web/20230516190231/https://books.google.com/books?id=UEaEDwAAQBAJ&pg=PA259 |url-status=live }}</ref> The rash usually appears one to two days later, but may appear before or up to seven days following feeling ill.<ref name=CDC2022/> 

It generally hurts to swallow.<ref name=CDC2022/> However, not all cases present with a fever, the degree of tiredness may vary, the sore throat and tongue changes might be slight or absent, and in some the rash can be patchy rather than diffuse.<ref name=Zitelli2023/>{{page needed|date=December 2022}} Cough, hoarseness, runny nose, diarrhea, and [[conjunctivitis]] are typically absent in scarlet fever; such symptoms indicate what is more likely a viral infection.<ref name=Wessels2016/>

===Mouth and throat===
[[File:Pos strep.JPG|thumb|upright|Throat of a child with a positive throat culture for streptococcal pharyngitis]]
[[File:Streptococcal pharyngitis.jpg|thumb|Streptococcal pharyngitis with red throat/uvula and spots on roof of mouth]]

[[Streptococcal pharyngitis|Strep throat]] is usually associated with fatigue and a fever of over 39&nbsp;°C (102.2&nbsp;°F).<ref name=Wessels2016>{{Cite book|url=https://www.ncbi.nlm.nih.gov/books/NBK333418/|title=Streptococcus pyogenes: Basic Biology to Clinical Manifestations|last=Wessels|first=Michael R.|chapter=Pharyngitis and Scarlet Fever|date=2016|publisher=University of Oklahoma Health Sciences Center|editor-last=Ferretti|editor-first=Joseph J.|location=Oklahoma City (OK)|pmid=26866221|editor-last2=Stevens|editor-first2=Dennis L.|editor-last3=Fischetti|editor-first3=Vincent A.|access-date=28 January 2018|archive-date=3 March 2021|archive-url=https://web.archive.org/web/20210303033712/https://www.ncbi.nlm.nih.gov/books/NBK333418/|url-status=live}}</ref> The tonsils may appear red and enlarged and are typically covered in [[exudate]].<ref name=Andrew2020/> The throat may be red with [[Forchheimer spots|small red spots]] on the [[soft palate|roof of the mouth]].<ref name=Pardo2022/> The [[palatine uvula|uvula]] can look red and swollen.<ref name=Zitelli2023/> 30% to 60% of cases have associated enlarged and tender [[cervical lymph nodes|lymph nodes]] in the neck.<ref name=Zitelli2023/> During the first two days of illness the tongue may have a whitish coating from which red swollen [[lingual papillae|papillae]] protrude, giving the appearance of a "white strawberry tongue".<ref name=Zitelli2023/> After four to five days when the white coating sheds it becomes a "red strawberry tongue".<ref name=Zitelli2023/> The symptomatic appearance of the tongue is part of the rash that is characteristic of scarlet fever.<ref name="Ferri-2018">{{Cite book |title=Ferri's Clinical Advisor 2018 |last=Ferri|first=Fred|publisher=Elsevier|year=2018|pages=1143}}</ref><ref name="Goldsmith-2012">{{Cite book|title=Fitzpatrick's Dermatology in General Medicine |last1=Goldsmith|first1=Lowell|last2=Katz|first2=Stephen|last3=Gilchrist|first3=Barbara|last4=Paller|first4=Amy|last5=Leffell|first5=David|last6=Wolff|first6=Klaus|publisher=McGraw Hill|year=2012}}</ref><ref name="Usatine-2013">{{Cite book|title=Color Atlas of Family Medicine, Second Edition|last=Usatine|first=Richard|publisher=McGraw Hill Companies|year=2013}}</ref>

===Rash===
[[File:Scarlet fever 2.jpg|thumb|upright|Scarlet fever rash in light skin]]
[[File:Scarlet fever rash.jpg|thumb|upright|Scarlet fever rash in dark skin]]
[[File:Scarlet fever 1.1.JPG|thumb|right|Red cheeks and pale area around the mouth in scarlet fever]]
[[File:Scarlet Fever.jpg|thumb|upright|Characteristic red cheeks and rash of scarlet fever]]

The characteristic rash has been denoted as "scarlatiniform", and it appears as a diffuse redness of the skin with small bumps resembling goose bumps.<ref name="Kaspar-2015">{{Cite book|title=Harrison's Principles of Internal Medicine, 19th edition|last1=Kaspar|first1=Dennis|last2=Fauci|first2=Anthony|last3=Hauser|first3=Stephen|last4=Longo|first4=Dan|last5=Jameson|first5=J. Larry|last6=Loscalzo|first6=Joseph|publisher=McGraw Hill Education|year=2015}}</ref> It typically appears as small [[macule|flat spots]] on the neck or torso before developing into [[papule|small bumps]] that spread to the arms and legs.<ref name=Goldman2020>{{cite book |last1=Stevens |first1=Dennis L. |last2=Bryant |first2=Amy E. |last3=Hagman |first3=Melissa M. |editor1-last=Goldman |editor1-first=Lee |editor2-last=Schafer |editor2-first=Andrew I. |title=Goldman-Cecil Medicine |date=2020 |publisher=Elsevier |location=Philadelphia |isbn=978-0-323-55087-1 |page=1873 |edition=26th |volume=2 |chapter-url=https://books.google.com/books?id=7pKqDwAAQBAJ&pg=PA1873 |language=en |chapter=274. Nonpneumococcal streptococcal infections and rheumatic fever |access-date=30 January 2023 |archive-date=9 April 2023 |archive-url=https://web.archive.org/web/20230409103645/https://books.google.com/books?id=7pKqDwAAQBAJ&pg=PA1873 |url-status=live }}</ref> It tends to feel rough like sandpaper.<ref name=Cohen2022>{{cite book |last1=Denny |first1=George O. |last2=Cohen |first2=Bernard A. |editor1-last=Cohen |editor1-first=Bernard A. |title=Pediatric Dermatology |date=2022 |publisher=Elsevier |location=Philadelphia |isbn=978-0-7020-7963-4 |page=191-192 |chapter-url=https://books.google.com/books?id=5cM2EAAAQBAJ&pg=PA192 |language=en |chapter=7. Reactive erythema |access-date=30 January 2023 |archive-date=7 April 2023 |archive-url=https://web.archive.org/web/20230407141819/https://books.google.com/books?id=5cM2EAAAQBAJ&pg=PA192 |url-status=live }}</ref> The cheeks might look flushed with a pale area around the mouth.<ref name=CDC2022/> The scarlet fever rash generally looks red on white and pale skin, and might be difficult to visualise on brown or black skin, in whom the bumps are typically larger, the skin looks like sandpaper, and the perioral pallor less obvious.<ref name=Zitelli2023/> The palms and soles are spared.<ref name=Goldman2020/> The reddened skin blanches when pressure is applied to it.<ref name=Zitelli2023/> The skin may feel itchy, but is not painful.<ref name=Zitelli2023/> A more [[Pastia's lines|intense redness]] on the inside of skin folds and creases might be noticed.<ref name=Pardo2022>{{cite journal |last1=Pardo |first1=Salvatore |last2=Perera |first2=Thomas B. |title=Scarlet Fever |journal=StatPearls |date=2022 |pmid=29939666 |url=https://pubmed.ncbi.nlm.nih.gov/29939666/ |publisher=StatPearls Publishing |access-date=17 December 2022 |archive-date=23 March 2022 |archive-url=https://web.archive.org/web/20220323045123/https://pubmed.ncbi.nlm.nih.gov/29939666/ |url-status=live }}</ref> These are lines of [[petechia]]e, appearing as pink/red areas located in arm pits and elbow pits.<ref name=Goldman2020/> It takes around a week for the main rash to disappear.<ref name=CDC2022/> This may be followed by several weeks of peeling of the skin of typically fingers and toes.<ref name=CDC2022/> The desquamation process usually begins on the face and progresses downward on the body.<ref name=Zitelli2023/> Sometimes, this peeling is the only sign that scarlet fever occurred.<ref name=Andrew2020/> If the case of scarlet fever is uncomplicated, recovery from the fever and clinical symptoms, other than the process of desquamation, occurs in 5–10 days.<ref name=Marks2013/> After the desquamation, the skin will be left with a sunburned appearance.<ref name=Nelson2016>{{Cite book|title=Nelson Textbook of Pediatrics|last1=Kliegman|first1=Robert|last2=Stanton|first2=Bonita|last3=St Geme|first3=Joseph|last4=Schor|first4=Nina|publisher=Elsevier|year=2016|pages=1327–1337}}</ref>

===Variable presentations===
Children younger than five years old may have atypical presentations and many of the common signs and symptoms may be missing or different. Children younger than 3 years old can present with nasal congestion and a lower grade fever.<ref name="Langlois-2011">{{cite journal | vauthors = Langlois DM, Andreae M | s2cid = 207170856 | title = Group A streptococcal infections | journal =  Pediatrics in Review| volume = 32 | issue = 10 | pages = 423–9; quiz 430 | date = October 2011 | pmid = 21965709 | doi = 10.1542/pir.32-10-423 }}</ref> Infants may present with symptoms of increased irritability and decreased appetite.<ref name="Langlois-2011" />

===Complications===
The complications, which can arise from scarlet fever when left untreated or inadequately treated, can be divided into two categories: suppurative and nonsuppurative.<ref name=Pardo2022/>

[[Suppuration|Suppurative]] complications: These are rare complications that arise either from direct spread to structures that are close to the primary site of infection, or spread through the [[lymphatic system]] or blood. In the first case, scarlet fever may spread to the pharynx. Possible problems from this method of spread include peritonsillar or retropharyngeal abscesses, [[cellulitis]], [[mastoiditis]], or [[sinusitis]].{{citation needed|date=June 2021}}

In the second case, the streptococcal infection may spread through the [[lymphatic system]] or the blood to areas of the body further away from the pharynx. A few examples of the many complications that can arise from those methods of spread include [[endocarditis]], [[pneumonia]], or [[meningitis]].<ref name=Bennett2015>{{Cite book|title=Mandell, Douglas and Bennett's Principles and Practice of Infectious Disease, Eighth Edition|last1=Bennett|first1=John|last2=Dolin|first2=Raphael|last3=Blaser|first3=Martin|publisher=Saunders|year=2015|pages=2285–2299}}</ref>

Nonsuppurative complications: These complications arise from certain subtypes of group A streptococci that cause an autoimmune response in the body through what has been termed [[molecular mimicry]]. In these cases, the antibodies which the person's immune system developed to attack the group A streptococci are also able to attack the person's own tissues. The following complications result, depending on which tissues in the person's body are targeted by those antibodies.<ref name="Kaspar-2015"/>
* [[Acute rheumatic fever]]: This is a complication that results 2–6 weeks after a group A streptococcal infection of the upper respiratory tract.<ref name=Nelson2016/> It presents in developing countries, where antibiotic treatment of streptococcal infections is less common, as a febrile illness with several clinical manifestations, which are organized into what is called the [[Jones criteria]]. These criteria include arthritis, carditis, neurological issues, and skin findings. Diagnosis also depends on evidence of a prior group A streptococcal infection in the upper respiratory tract (as seen in streptococcal pharyngitis and scarlet fever). The carditis is the result of the immunologic response targeting the person's heart tissue, and it is the most serious sequela that develops from acute rheumatic fever. When this involvement of the heart tissue occurs, it is called [[rheumatic heart disease]]. In most cases of rheumatic heart disease, the mitral valve is affected, ultimately leading to [[Mitral valve stenosis|mitral stenosis]].<ref name="Langlois-2011"/> The link to rheumatic fever and heart disease is a particular concern in Australia, because of the high prevalence of these diseases in [[Aboriginal and Torres Strait Islander]] communities.<ref name=abcvirus/>
* [[Poststreptococcal glomerulonephritis]]: This is inflammation of the kidney, which presents 1–2 weeks after a group A streptococcal pharyngitis. It can also develop after an episode of [[Impetigo]] or any group A streptococcal infection in the skin (this differs from acute rheumatic fever which only follows group A streptococcal pharyngitis).<ref name=Nelson2016/><ref name="Tanz-2018" /> It is the result of the autoimmune response to the streptococcal infection affecting part of the kidney. Persons present with what is called acute [[nephritic syndrome]], in which they have high blood pressure, swelling, and urinary abnormalities. Urinary abnormalities include blood and protein found in the urine, as well as less urine production overall.<ref name=Nelson2016/>
* Poststreptococcal reactive arthritis: The presentation of arthritis after a recent episode of group A streptococcal pharyngitis raises suspicion for acute rheumatic fever, since it is one of the [[Jones criteria]] for that separate complication. But, when the arthritis is an isolated symptom, it is referred to as poststreptococcal reactive arthritis. This arthritis can involve a variety of joints throughout the body, unlike the arthritis of acute rheumatic fever, which primarily affects larger joints such as the knee joints. It can present less than 10 days after the group A streptococcal pharyngitis.<ref name=Nelson2016/>