Study on linear dermatoses
Keywords:Blaschko’s lines, Lichen striatus, Lichen planus
Background: The objective of the study was to study the incidence, age and sex distribution, association, distribution, clinical presentation, histopathological correlation of linear dermatoses at the skin Outpatient Department.
Methods: A prospective study was conducted over a period of 1 year in 90 patients, attending the Department of Dermatology, at a tertiary care hospital, Chennai. Data collection, clinical examination and skin biopsy were recorded and analyzed statistically. Inclusion criteria were all patient with linear dermatoses. Exclusion criteria were Koebner phenomenon.
Results: The incidence of linear dermatoses in our outpatient department- 0.2% per year. Among the linear dermatoses, lichen striatus was found to be the most common. The other dermatoses following Blaschko’s lines, in the descending order of frequency seen in this study were linear epidermal nevus, linear lichen planus, linear morphoea, inflammatory linear verrucous epidermal nevus, segmental vitiligo, hypomelanosis of ito, linear lichenoid dermatitis, linear psoriasis, segmental neurofibromatosis, linear whorled nevoid hypermelanosis, incontinentia pigmenti, nevus depigmentosus, linear porokeratosis. Female preponderance was noted. Majority of patients showed unilateral distribution mostly on the extremities.
Conclusions: Most of the linear lesions are arranged along Blaschko’s line. The importance of histopathological correlation is obvious. Cases which were clinically diagnosed as lichen striatus, showed histopathological features of psoriasis and linear epidermal verrucous nevus. One case diagnosed clinically as epidermal nevus was found to be super imposed by psoriasis histologically. Another case clinically diagnosed as linear psoriasis clinically, was found to be linear porokeratosis on histopathology. Very few associations were noted.
Blaschko A. Die Nervenverteilung in der Haut in ihrerBeziehungzu den Erkrankungen der Haut. Beilagezu den Verhandlungen der Deutschen Dermatologischen Gesellschaft VII Congress. Breslau; Braumuller, Wien. 1901.
Bolognia JL, Orlow SJ, Glick SA. Lines of Blaschko. J Am Acad Dermatol. 1994;31:157-90.
Montgomery DW. The cause of the streaks in naevuslinearis. J Cutan Genito-urinary Dis. 1901;19:455-64.
Happle R, Assim A. The lines of Blaschko on the head and neck. J Am Acad Dermatol. 2001;44:612-5.
Happle R. Mosaicism in human skin Understanding the patterns and mechanisms. Arch Dermatol. 1993;129:1460-70.
Hauber K, Rose C, Brocker EB, Hamm H. Lichen Striatus: Clinical features and follow up in 12 patients. Eur J Dermatol. 2000;10(7):536-9.
Boyd AS, Neldner KH. Lichen planus. J Am Acad Dermatol. 1991;25:593-619.
Elder DE, Elenitsas R, Johnson BL, Murphy GF, Xu X. Lever’S Histopathology of skin. 10th edition. 2008: 185-191.
Burns T, Breathnach S, Griffiths C, Cox N. Rook’s Textbook of Dermatology. Volume 1. 8th Edition. 2004: 18.4-18.5.
Burns T, Breathnach S, Griffiths C, Cox N. Rook’s Textbook of Dermatology. Volume 3. 8th Edition. 2004: 51, 69 and 70.
Falanga V, Medsger TA, Reichlin M, Rodnan GP. Linear Scleroderma: clinical spectrum, prognosis and laboratory abnormalities. Ann Intern Med. 1986;104:849-57.
Miller MT, Spencer MA. Progressive hemifacial atrophy (Parry-Romberg disease). J Pediatric Opphthalmol Strabismus. 1987;24:27-36.