This is a 15-year-old patient, with no family or personal history of interest, who comes to consultation for the insidious appearance, 3-4 days before, of erythematous lesions in a certain size that have changed color.
1.
The patient reported mild upper airway infection the previous week without any other symptoms.
She denied drug intake.
Physical examination revealed no fever.
Arterial pulse 110/70 mm Hg, heart rate: 60 beats per minute and normal cardiorespiratory auscultation.
The lesions present as erythematous cutaneous nodules slightly hyperthermic and painful to palpation, whose diameter ranges from 1 to 3 cm on the pretibial surface without observing lesions in other locations.
Patient rest is recommended, as well as analgesia with paracetamol or NSAIDs, and she is referred to the dermatology department for confirmatory biopsy.
Since the physical examination of the patient is normal, complementary tests are requested to arrive at the diagnosis and etiology of anemia: anti-nuclear antibody formula, count and VSG; biochemistry with liver, kidney and thyroid function tests; rheumatoid protein;
All values were within normal limits.
A chest X-ray was also requested, with no pathological findings; Mantoux negative; ASLO negative; serology Epstein-Barr virus (VEB), with positive IgG, negative; test negative pregnancy.
After 15 days, the lesions had almost disappeared.
The biopsy gave the definitive diagnosis.
Given the results of the complementary tests and the evolution of the patient, it was labelled as erythema nodosum of idiopathic etiology.
