In their article, Rodríguez-Bandera et al1 describe interesting ultrasound features of idiopathic facial aseptic granuloma (IFAG), including a lesion axis that tends to lie parallel to the skin surface and the presence of hypervascularization in the periphery of the lesion during the most inflammatory phase. Their description of the shape, echogenicity, and location of the lesion is similar to that of Vázquez-Osorio et al2: an ovoid, hypoechoic lesion located predominantly in the dermis. The features described by both authors are consistent with our ultrasound findings in IFAG patients.

The authors propose that the hyperechogenicity in the hypodermis underlying the lesion is indicative of edema in the subcutaneous adipose tissue surrounding the lesion. While I agree that this hyperechogenicity may be secondary to tissue inflammation, one could argue that it is further enhanced by the perilesional hypervascularization that predominates in the sublesional part. Posterior acoustic reinforcement artifact, which is typical of fluid-containing structures, could be generated by these dilated blood vessels, subsequently attenuating with the reduction in inflammation and consequent decreases in vessel caliber and hypervascularization.

The use of ultrasound to define lesion patterns, establish differential diagnoses with other skin conditions,3 and perform noninvasive follow-up can greatly facilitate early diagnosis and help avoid unnecessary biopsy. The role of ultrasound is of particular importance in the case of IFAG, which is primarily a disease of childhood and tends to affect the face.