Successful treatment of ulcerative and diabeticorum necrobiosis lipoidica with intravenous immunoglobulin in a patient with common variable immunodeficiency.

Discussion |Threemuscles, thecircularorbicularis oris, depressor labii inferioris, andmentalis align the labiomental fold or cross it as they pass to their insertion.2 The fibers of the 3 muscles are attached to the skin by thick bands of fibroelastic fibers. Thementalismuscles originate from themandible and serve as paired elevators of the central lower lip.3 They usually overlap and insert into the deep dermis of the chin pad. Patientswith substantial overlapof thementalismuscles tend to have a deep labiomental fold.3 The presence of a deep labiomental fold isa relativelycommonconditionandmaysometimescauseanaesthetic concern.4Procedures for treatingdeep labiomental fold are sometimes discussed in the plastic surgery literature, but it has been rarely reported in the dermatology literature. To our knowledge, this is the first report of a dermatologically related condition associated with this fold. Another prevalent transverse linear crease of the face, the nasal crease, appears across the lower third of the nasal dorsum. Insomecases, changesofpigmentation,milia,orpseudocomedones arepresent along thenasal crease.5 Transversenasal milia in the absence of a transverse nasal crease are less frequently reported. Recently, our research team6 reported a case of seborrheic keratosis–like hyperplasia and horn cysts alignedalong this crease.These findingswereattributed to the fact that the triangular cartilage and the alar cartilage attach ina linear fashionat the junctionof themiddle and lower third of thenose,producingapotential embryonic fault line inwhich retention cysts presenting asmilia andcomedones canoccur.5 Early acne lesions favor the forehead, nose, and chin in many children. Although many times overlooked, the external ear is another common location for open and closed comedones in young patients with acne.7 We think that the commonconcavesurfaceof thenasal crease,deep labiomental fold, and external earmay facilitate the appearance of retention lesions in those locations. In conclusion,we think that the labiomental fold, a transverse fold of the chin, can harbor retention cysts or comedones in a similar fashion to the nasal crease. Dermatologists should be aware of this fold, since it might be encountered in the dermatology practice and may be associated with additional dermatologic conditions.