DR [Dermatology Reports 2011; 3:e22] [page 49] The appearance of angiolipomatosis after using laptop computer on the thighs: a relationship? Marie Caucanas,1 Gebhard Müller,2 Olivier Vanhooteghem1 1Department of Dermatology, Clinique Sainte Elisabeth, Namur; 2Institute of Pathology and Genetics, Gosselies, Belgium Abstract A 56-year-old patient developed angiolipo- matosis of the anterior part of the thighs after repeated laptop contact localisation. Histolog- ical findings exhibit an unusual inflammatory infiltrate. We postulate that the computer could favour lipoma development by a phys- iopathological mechanism that remains to be clarified. Case Report A 56-year-old woman gradually developed subcutaneous nodules on the thighs over the course of two years. The patient has no med- ical or familial history and does not take any medication. She is a speech specialist and ad- mits working several times a week for a couple of hours with her laptop over her thighs. Clin- ical examination shows the existence of ap- proximately ten nodules strictly localised on the anterior part of the thighs (Figure 1), sug- gesting clinical lipomatosis. An excisional biopsy of a nodule shows angi- olipomatosis with mild to moderate inflamma- tory infiltrate with CD68-positive macrophages and T lymphocytes (Figure 2). The patient stopped putting her laptop on her thighs for one year and observed stabilisa- tion of nodule count number, but no regression was noted. Discussion This is the first description of a secondary lipomatosis of the thighs with the regular use of a laptop computer on this specific lo- cation. Histological examination shows an- giolipomatosis associated with an inflamma- tory infiltrate of histiocytes and T lympho- cytes. According to the imputability criteria,1 it is highly plausible that the use of the laptop in contact with the thighs caused the development of underlying lipomas, as the rapid onset of nodules was observed with the use of the laptop, and the stabilisation of the lesions was observed after the laptop was no longer used at that location. This suggests a symmetric semiology and parallel evolution, and the absence of any other explanation for the condition after full examination supports this conclusion despite the absence of any reliable specific complementary examina- tion proving the link of causality to the his- tological findings. We think that the laptop is responsible for the development of the lipomas. The inflammation found upon histo- logical examination could have been provoked by the computer through an unknown mecha- nism and could involve the influence of the heat emitted by the battery and/or the electro- magnetic waves emanating from the device. After changing her working habits, the number of lipomas stabilised but did not regress. The use of new technologies, which con- tinue to development and become more acces- sible, were recently associated with unsus- pected pathologies. The semicircular lipoat- rophy of the thighs, described by a series of hundreds of patients in companies equipped with the most recent models of fixed com- puters, is secondary to electromagnetic lipol- ysis, which is facilitated by local circumstances such as the conductivity of the material of the desks, the ambient humidity and the inappro- priate insulation of computer wiring.2-6 Five cases of erythema ab igne dermatitis de- veloped after regular use of a laptop on the thighs have been described since 2004.7-14 As suggested by the case of our patient, the devel- opment of lipoma could be a consequence of the extensive usage of the computer with imme- diate contact on the body. The exact phys- iopathological mechanism behind this pathology remains to be clarified. References 1. Bégaud B, Evreux JC, Jouglard J, Lagier G. Imputabilité des effets inattendus ou tox- iques des médicaments. Actualisation de la méthode utilisée en France. Therapie 1985;40:111-8. 2. Flagothier C, Quatresooz P, Pierard G-E. Electrolipolysis and semicircular lipoat- rophy of the thighs. Ann Dermatol Venereol 2006;133:577-80. 3. Panella H, Juanola E, de Peray JL, Artazcoz L. Semicircular lipoatrophy : a new occupa- tional disease. Gac Sanit 2008;22:73-5. 4. Lachapelle JM, Tennstedt D. Nouvelles dermatoses de l’environnement. Progrès en dermato-allergologie. Dijon 2002. Ed. E. Collet. John Libbey Eurotext, Montrouge 2002,pp.157-65. 5. Hermans V, Hautekiet M, Haex B, Spaepen AJ, Van der Perre G. Lipoatrophia semicir- cularis and the relation with office work. Applied Ergonomics 1999;30:319-24. 6. Curvers B, Maes A. Lipoatrophia semicir- cularis: a new office disease? 900 cases re- ported in Belgium. www.next-up.org Dermatology Reports 2011; volume 3:e22 Correspondence: Olivier Vanhooteghem, Sainte Elisabeth Hospital, Dermatology Unit, Namur, Belgium. E-mail: ovanhooteghem@hotmail.com Key words: lipoma, angiolipomatosis, laptop com- puter, electromagnetic waves, thighs, nodules. Conflict of interest: all authors certified that they have no conflicts of interest, including specific financial interests and relationships and affilia- tions relevant to the subject of this manuscript. Received for publication: 6 August 2011. Accepted for publication: 9 August 2011. This work is licensed under a Creative Commons Attribution NonCommercial 3.0 License (CC BY- NC 3.0). ©Copyright M. Caucanas et al., 2011 Licensee PAGEPress, Italy Dermatology Reports 2011; 3:e22 doi:10.4081/dr.2011.e22 Figure 1. Lipomatosis of the anterior part of the thigh. Figure 2. Inflammatory infiltrate associat- ed with angiolipomatosis. No n- co mm er cia l u se on ly [page 50] [Dermatology Reports 2011; 3:e22] 7. Bilic M, Adams BB. Erythema ab igne in- duced by a laptop computer. J Am Acad Dermatol 2004;50:973-4. 8. Jagtman BA. Erythema ab igne due to a laptop computer. Contact Dermatitis 2004;50:105. 9. Maalouf E, Simantov A, Rosenbaum F, Chosidow O. Erythema ab igne as an unex- pected computer side-effect. Dermatology 2006;212:392-3. 10. Mohr MR, Scott KA, Pariser RM, Hood AF. Laptop computer-induced erythema ab igne: a case report. Cutis 2007;79: 59-60. 11. Levinbook WS, Mallett J, Grant-Kels JM. Laptop computer associated erythema ab igne. Cutis 2007;80:319-20. 12. Bachmeyer C, Bensaid P, Bégon E. Laptop computer as a modern cause of erythema ab igne. J Eur Acad Dermatol Venereol 2009;23:736-7. 13. Fite C, Bouscarat F. Laptop computer-in- duced erythema Ab Igne. Presse Med 2009; 38:1164-5. 14. Gohar A. 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