What could be causing my scattered, non-raised rash over my abdomen, legs, and arms, accompanied by swollen cervical lymph nodes, a red throat, and a cough?

Differential Diagnosis: Viral Exanthem vs. Streptococcal Pharyngitis

Your presentation of scattered non-raised rash with swollen cervical lymph nodes, red throat, and cough most likely represents a viral upper respiratory infection with associated viral exanthem, though streptococcal pharyngitis with scarlet fever must be ruled out immediately. 1

Immediate Diagnostic Steps

Rule Out Group A Streptococcal Pharyngitis First

You need a throat culture or rapid antigen detection test (RADT) immediately because clinical findings alone cannot differentiate streptococcal from viral pharyngitis, even for experienced clinicians. 1 The combination of red throat, cervical lymphadenopathy, and rash could represent scarlet fever from Group A Streptococcus (GAS), which requires antibiotic treatment to prevent rheumatic fever. 1

Key features that increase suspicion for GAS pharyngitis include: 1

• Sudden-onset sore throat with pain on swallowing
• Fever (typically 101°F to 104°F)
• Tender, enlarged anterior cervical lymph nodes
• Tonsillopharyngeal erythema
• Scarlatiniform rash (though your rash is described as non-raised and scattered, which is less typical)

Features Favoring Viral Etiology

The presence of cough strongly suggests a viral cause rather than streptococcal pharyngitis. 1 Cough, along with coryza, hoarseness, and conjunctivitis, are clinical findings highly suggestive of viral pharyngitis. 1

Your scattered, non-raised rash pattern is more consistent with a viral exanthem than the typical scarlatiniform (sandpaper-like) rash of scarlet fever. 1, 2

Most Likely Diagnosis: Viral Upper Respiratory Infection

This presentation is most consistent with a viral respiratory infection causing both upper airway symptoms and a maculopapular viral exanthem. 3, 4 Common viral causes include: 1

• Epstein-Barr virus (infectious mononucleosis)
• Adenovirus
• Enteroviruses
• Respiratory syncytial virus
• Influenza or parainfluenza viruses

The temporal pattern of rash appearing with respiratory symptoms and cervical lymphadenopathy is classic for viral exanthems. 5, 6

Management Algorithm

Step 1: Obtain Throat Testing

• Get rapid strep test or throat culture to definitively rule out GAS pharyngitis 1
• If positive: Start antibiotics immediately (penicillin or amoxicillin) to prevent rheumatic fever 1
• If negative: Proceed with supportive care for viral illness 1

Step 2: Assess for Warning Signs

Check for features requiring immediate escalation: 1, 3

• Difficulty breathing or swallowing
• High persistent fever
• Signs of dehydration
• Petechial or purpuric rash (suggests meningococcemia or other serious bacterial infection) 2, 6
• Severe systemic toxicity

Step 3: Symptomatic Management for Viral Illness

If strep test is negative, treat supportively: 1, 3

• Adequate hydration
• Antipyretics for fever
• For cough: First-generation antihistamine/decongestant combination starting once daily at bedtime 3
• Throat lozenges or warm liquids for throat discomfort 3

Step 4: Follow-Up Timing

• Reevaluate within 7-10 days if symptoms fail to improve or worsen 3, 4
• Most viral respiratory infections with cough resolve within 3 weeks 1, 4
• If cough persists beyond 8 weeks, systematic evaluation for chronic cough causes becomes necessary 4

Critical Pitfalls to Avoid

Do not empirically treat with antibiotics without confirming streptococcal infection. 1 Routine antibiotic treatment for acute bronchitis and viral pharyngitis is not justified and should not be offered. 1

Do not dismiss cervical lymphadenopathy as benign without proper evaluation. 1 While viral infections commonly cause reactive lymphadenopathy, persistent or progressive lymph node enlargement requires further investigation. 7

Do not assume this is "just viral" if the patient has immunocompromising conditions. 1 Immunosuppressed patients can present with atypical manifestations of serious infections. 8