Persistent Linear Bands in Infancy Acquired After Local Pressure: A Consequence of Mast Cell Activation? Lara S. Ford, B.Sc., M.B.B.S.,* Maureen Rogers, M.B.B.S., F.A.C.D.,  Andrew S. Kemp, M.B.B.S., F.R.A.C.P., Ph.D., and Dianne E. Campbell, M.B.B.S., F.R.A.C.P., Ph.D.  *Department of Pediatrics, University of Massachusetts Medical School, Worcester, Massachusetts,  Children’s Hospital Westmead, University of Sydney, Sydney, Australia Abstract: A 10-month-old girl with marked symptomatic dermographism presented with linear bands at the sock line noted to have developed following an episode of localized urticaria and angioedema at the sock line. We speculate that release of mast cell mediators associated with the dermo- graphism may have triggered the development of the linear bands. Raised linear bands in infancy have been described as developing in the first months of life. Four previous occurrences have been reported (1–3). The etiology is unclear, however it was speculated that the mechanism was related to that causing constriction bands (1). We describe an infant with marked dermographism who developed linear bands at the sock line following an episode of pressure from the elasticized bands of her socks at 6 weeks of age. CASE REPORT A female full term infant was noted to have marked dermographism from birth, with significant erythema and recurrent episodes of cutaneous whealing. She had had ‘‘sensitive’’ skin since birth and her mother des- cribed multiple episodes of urticaria which occurred on an almost daily basis without an obvious precipitant. She had also had multiple episodes of facial rashes, and one of lip angioedema, following ingestion of several foods. Her mother also described one particular episode at the age of 6 weeks immediately prior to the onset of the linear bands. One night she had dressed the patient in a terry toweling coverall with built-in bootees, and in addition placed ankle socks over the top. When the patient’s mother undressed her in the morning she found her feet and ankles markedly swollen, with purple discoloration overlying the swell- ing at the line of the elasticized sock tops. No break in skin integrity was noted. The mother was very sure that no such lesions had been present over this area prior to 6 weeks of age. She had not used elasticized socks previously and did not use them after the bands developed. Over the next 2 weeks horizontal raised linear bands developed along the sock line on both legs, at the site which had been maximally affected by each sock. The bands were still present at 2 years of age. Address correspondence to Dianne E. Campbell, M.B.B.S., F.R.A.C.P., Ph.D., Discipline of Paediatrics and Child Health, CHW, Westmead, Sydney, NSW 2145, Australia, or e-mail: campbell@med.usyd.edu.au. DOI: 10.1111/j.1525-1470.2007.00456.x Ó 2007 The Authors. Journal compilation Ó 2007 Blackwell Publishing, Inc. 391 Pediatric Dermatology Vol. 24 No. 4 391–393, 2007