Red Macule

CLINICAL DIAGNOSTIC MANUAL

A red macule is a flat, red skin lesion that can vary in size and shape. These macules result from local vasodilation, inflammation, or blood extravasation in the skin. A red macule can be indicative of various pathologies, ranging from allergic reactions to viral infections and drug reactions. Accurate identification of the underlying cause is crucial for proper management and treatment.

Pathology	Symptoms and Clinical Signs	Suspected Diagnosis	Confirmatory Diagnosis
Drug reaction	Red macules, itching, widespread rash. History of recent medication use.	Medical history and physical examination. Evaluation of recent medications.	Confirmation with drug discontinuation and observation of rash resolution.
Allergy	Red macules, itching, hives. History of exposure to known allergens.	Medical history and physical examination. Allergy skin tests.	Confirmation with positive allergy skin tests.
Viral exanthem of unknown cause	Red macules, fever, mild systemic symptoms. History of recent viral infection.	Medical history and physical examination. Exclusion of other specific causes.	Clinical diagnosis based on presentation and exclusion of other causes.
Measles	High fever, cough, conjunctivitis, maculopapular rash starting on the face. Koplik spots in the oral mucosa.	Medical history and physical examination. Serology for measles IgM/IgG.	Confirmation with positive measles serology.
Rubella	Low-grade fever, lymphadenopathy, maculopapular rash starting on the face. Joint pain (in adults).	Medical history and physical examination. Serology for rubella IgM/IgG.	Confirmation with positive rubella serology.