Infantile transient smooth muscle contraction of the skin: a case report and literature review

Abstract

A male infant was delivered by Caesarean section in the 34th week of gestation due to painful uterine contractions and breech position of the baby. He was intubated on his first day of life due to immature lungs and persistent pulmonary hypertension, and was extubated three days later. On the 5th6th day of life, the parents noticed attacks of skin rippling, mostly on his thighs and buttocks, but also on his arms and face. The attacks were triggered by mild friction and cold air exposure, but also developed spontaneously. Between episodes of rippling, the skin had a normal appearance. The boy underwent complete clinical evaluation. There were no signs of neurological disease nor other medical conditions. Laboratory work-up, including complete blood count, Creactive protein, creatinine, liver function tests, Na+, K+ Ca++, and Mg++, showed normal values. Upon clinical examination, we noticed that the surface of the thighs began to dimple and ripple suddenly, and then became smooth again after 2 to 10 seconds. The infant did not seem to be disturbed during the attacks of involuntary skin movement. The frequency of the attacks was initially every 5 to 10 minutes and diminished gradually (figure 1). Histopathological examination of a skin biopsy showed no overt abnormality apart from moderate hyperplasia of smooth muscle bundles in the dermis. No smooth muscle hamartoma was identified. The frequency of the episodes diminished slowly with time and disappeared at the age of 18 months. Transient rippling of the skin in healthy infants is rarely reported in the literature. To the best of our knowledge, this phenomenon is not described in dermatology textbooks. Fine et al. [1] were the first to report a healthy male infant with spontaneous rippling of the skin of the whole body (except the face). The phenomenon lasted about 30 seconds and multiple attacks were noted during the clinical examination. No skin biopsy specimen was obtained due to refusal by the parents.