Chapter 34. Scarlet Fever and Strawberry Tongue

A 7-year-old boy is brought to the family physician's office with a rough red rash on his trunk (Figures 34-1 and 34-2) along with fever and a sore throat. The sandpaper rash and signs consistent with strep pharyngitis lead the physician to diagnose scarlet fever. The physician explains the diagnosis to the mother and oral Pen VK is prescribed. The boy feels markedly better by the next day, and the mother continues to give the penicillin for the full 10 days as directed to prevent rheumatic fever.

Scarlet fever is an illness caused by toxin-producing group A β-hemolytic streptococci. Most commonly, scarlet fever evolves from an exudative pharyngitis.

Strawberry tongue may be observed in patients with scarlet fever, and usually develops within the first 2 to 3 days of illness. A white or yellowish coating usually precedes the classic red tongue with white papillae (Figure 34-3).

• Scarlet fever is predominately seen in school-age children with no gender predilection.
• Majority related to strep pharyngitis, with 1 in 10 developing scarlet fever (Figures 34-1, 34-2, and 34-4).
• Prevalent in late fall to early spring.
• Strawberry tongue (Figure 34-4) is most commonly seen in children in association with scarlet fever or Kawasaki disease.
• Can be present with other group A Streptococcus (strep) infection.
• In cases of strep, a white membrane through which the papillae are seen can initially cover the tongue followed by desquamation of the membrane (with the appearance as in Figure 34-4).

• Transmission of Streptococcus occurs via respiratory secretions.
• Virulent Streptococcus pyogenes (group A Streptococcus or GAS) incubate more than 2 to 7 days. M protein serotypes of GAS are typically more invasive with greater potential for progression to rheumatic fever or acute glomerulonephritis if untreated.1
• Fever and rash are related to pyrogenic A-C and erythrogenic exotoxins produced by GAS.2
• Infection may originate from other sites like skin (e.g., cellulitis), and seed blood (bacteremia) or organ systems (e.g., pneumonia).
• Strawberry tongue results from a general inflammatory response during the early course of the disease.

Clinical Features

• Headache, sore throat, cervical lymphadenopathy, abdominal pain, nausea and vomiting, decreased oral intake, malaise, and fever may precede rash. Cough is usually not present.
• Oropharyngeal findings include:
  • Strawberry tongue—Erythematous and sometimes edematous tongue with prominent papillae (Figure 34-4).
• May be covered by a white membrane/coating through which the papillae can be seen.
• Not typically painful.
• Forchheimer spots—Palatal and uvular petechiae and erythematous macules.
• Initial sandpaper rash, associated with blanching erythema and occasional pruritus, erupts in 1 to 2 days (Figures 34-1, 34-2, and 34-3).2
• Pastia's lines are pink or red lines seen in the body folds (especially elbows and axilla) during scarlet fever. Linear hyperpigmentation may persist after the rash fades (Figure 34-1).
• Desquamation of the skin (especially of the hands and feet) ensues in 3 to 4 days as rash fades and can persist for 2 to 4 weeks.1

Typical Distribution

• Progresses centrally (torso) to peripherally (extremities) and can be prominent on the face, chest, palms, fingers, and toes.1

Laboratory Tests and Imaging

• Throat swab for rapid strep testing (screening) and/or culture (confirmation) is usually performed.
• Complete blood count (CBC), if indicated, to look for:
  • Elevation of white blood cell count with left shift.
  • Elevated platelet count—Seen with Kawasaki disease (after 1 week).
• Antistreptolysin-O titer is obtained to confirm prior infection or support suspected poststreptococcal complication, such as rheumatic fever.3
• Acute phase reactants (C-reactive protein [CRP] and erythrocyte sedimentation rate [ESR]) may be elevated, and may be useful in monitoring nonsuppurative complications such as rheumatic fever.4
• If Kawasaki disease is suspected, two-dimensional echocardiography or angiography is obtained to detect coronary artery abnormalities. The initial echocardiogram should be performed as soon as the diagnosis is suspected to establish a baseline for longitudinal follow-up of coronary artery morphology, left ventricular and left valvular function, and the evolution and resolution of pericardial effusion when present.4 SOR C

The rash of scarlet fever may be confused with the following:

• Allergic/contact dermatitis—Often localized to areas of contact; prominent pruritus and skin vesicles often in linear streaks (see Chapter 145, Atopic Dermatitis and Chapter 146, Contact Dermatitis).
• Viral exanthem—Many viral exanthems have prodromal phases with fever followed by skin rashes that can be macular or maculopapular including measles (see Chapter 126, Measles), rubella (tender retroauricular, cervical, and occipital lymphadenopathy, and rash starts on face and spreads and fades quickly), and roseola (rash occurs at the end of a period of 3 to 5 days of high fever). Lack of sandpaper feel and oral findings help distinguish.
• Staphylococcal scalded skin syndrome—Rash may also follow a prodrome of malaise and fever but is macular, brightly erythematous, and initially involves the face, neck axilla, and groin. Skin is markedly tender and large areas of the epidermis peel away.
• Erythema toxicum—Rash of newborns; often blotchy, evanescent, macular erythema that can include pale yellow or white wheals or papules on an erythematous base (see Chapter 108, Normal Skin Changes).

The differential diagnosis for strawberry tongue includes:

• Kawasaki disease (Figure 34-5)—Fever persists at least 5 days and there must be the presence of at least four principal features including the following:4
  • Changes in extremities—Acute: Erythema of palms, soles; edema of hands and feet. Subacute: Periungual peeling of fingers and toes in weeks 2 and 3.
  • Polymorphous exanthem.
  • Bilateral bulbar conjunctival injection without exudate.
  • Changes in lips and oral cavity—Erythema, lips cracking, strawberry tongue, diffuse injection of oral and pharyngeal mucosae.
  • Cervical lymphadenopathy (>1.5 cm diameter), usually unilateral.
• Viral stomatitis with eruptive lingual papillitis—Lack of other features for scarlet fever or Kawasaki's will assist in differentiating.
• Red-colored food dyes—History is helpful; edema and prominent papillae will be absent.

Nonpharmacological

• Supportive care with oral fluids and age-appropriate symptomatic measures, such as salt-water gargles, and an antipyretic as needed are recommended.

Medications

• For scarlet fever and strawberry tongue caused by group A Streptococcus:
  • Oral penicillin (penicillin VK 500 mg divided twice daily or 250 mg divided 4 times daily for 10 days for adults or 25 to 50 mg/kg per day divided 4 times daily for 10 days for children) or macrolide (erythromycin base 500 mg 4 times daily for 10 days for adults or erythromycin estolate 20 mg/kg per day or succinate 40 mg/kg per day divided twice daily for 10 days for children) in penicillin-allergic patients for 10 days.5 SOR A
  • Cephalosporins are an efficacious alternative (e.g., cefuroxime axetil 250 mg twice daily for 10 days for adults or 20 mg/kg per day divided twice daily for 10 days for children); cephalosporins were better than penicillin in a metaanalysis.6 SOR A
  • Symptoms typically resolve in 4 to 7 days.
• For strawberry tongue caused by Kawasaki disease:
  • Intravenous gammaglobulin (IVIG), 2 g/kg in a single infusion, within 7 to 10 days of onset for Kawasaki disease to reduce subsequent coronary artery abnormalities.4 SOR A Additional IVIG infusion may be considered if defervescence is not achieved in the first 1 to 2 days.7
  • In the acute phase, aspirin is also administered at 80 to 100 mg/kg per day in 4 doses with IVIG followed by low-dose aspirin (3 to 5 mg/kg per day) until the patient shows no evidence of coronary changes by 6 to 8 weeks after the onset of illness.4 SOR C

Referral or Hospitalize

• Hospitalization should be considered if a patient is dehydrated or exhibits cardiorespiratory instability. It should also be considered for cases of complicated scarlet fever, streptococcal toxic shock, staphylococcal scalded skin, rheumatic fever, acute glomerulonephritis, or Kawasaki disease (when suspected).
• Cardiology, infectious disease, or nephrology consultation may be indicated in the most severe cases.

Scarlet fever usually follows a benign course. Rarely it is complicated by septic shock and multi-organ failure, suppurative complications such as peritonsillar abscess, or nonsuppurative complications such as rheumatic fever or poststreptococcal glomerulonephritis

• Routine follow-up is not required unless illness is protracted or a complication is suspected.
• For patients with uncomplicated Kawasaki disease, echocardiographic evaluation should be performed at the time of diagnosis, at 2 weeks, and at 6 to 8 weeks after onset of the disease.4 SOR C Recent studies show that repeat echocardiography performed 1 year after the onset of the illness is unlikely to reveal coronary artery enlargement in patients whose echocardiographic findings were normal at 4 to 8 weeks.4

• Contact physician for fever recurrence, atypical or persistent rash, and new symptoms or potential complications (meningitis, sinusitis, otitis media, oropharyngeal abscess, pneumonia, acute glomerulonephritis, or rheumatic fever).
• Completion of a prescribed antibiotic course is encouraged to decrease the incidence of recurrence and potential complications.3