No abstract

Immunohistochemistry was applied in the investigation of the possible existence of serotonin in human skin. It was found that epidermal melanocytes express a serotonin-like immunoreactivity. The immunoreactivity was associated with both the cytoplasm and the cellular membrane, though the latter was only found in certain cells. The serotonin anti-serum labeled the same cells as NKI-beteb, which is known as a reliable marker of melanocytes. Blocking experiments showed that both serotonin and NKI-beteb have different epitopes in the melanocytes. In in vitro studies, serotonin-like immunoreactivity appeared in approximately 90% of cultured human melanocytes, and was found both in the cytoplasm and also in the nuclei. Thus, we believe the melanocytes to be the origin of serotonin (or a serotonin-like molecule) in the skin.

By definition, normal healthy volunteers are assumed not to react to a TV/PC screen provocation. To our great surprise, this proved not to be true. The present results might lay a foundation to understand the underlying cause of so-called "screen dermatitis" with special reference to mast cells. However, blind or double-blind experiments using patients ought to be further investigated in order to find out the exact cause for the observed changes. Such causes include the effects of surrounding airborne chemicals, stress factors, etc.

Skin changes in ''screen dermatitis" versus classical UV-and ionizing irradiation-related damage -similarities and differences Two neiiroscieiitists' speculative review (jatigi S. .lohanssoti O. Skin cbatiges iti "screen dertnalilis" \orstts classical L'V-atui iotiizing irradialion-rclatcd damage -similarities and dilTcrences. Two tieuroscietilists' speculative rc\ie\v. Exp Dermalol 1997: 6: 28.^ 291. t^ Munksgaard. 1997 Abslracl: Ati increasing tnnnbcr of persotis sa\ thai llic\ gel cutaticous protilctns as well as sympicims ltoni ccrtatti ititcrtial orgatis, sttch as ihe cetitral ncr\otts s_\sleni (CNS) and llio heart, when beitig close lo cicclric cqtiiptiicnt. A major group of Ihcsc patients arc llic users of \ideo display Icrtiiinals (VDTs). who claitn lo ha\e subjcclixc atid objccli\c skinatid tnucosa-related sytnplotiis. sticli as pain. ilcb. heal sctisation. cryllictna, pajiules. and intslulcs. The CNS symplotns arc, e.g. di/ziticss. tiredness, atid headache. Rrylhetna. ilcli. heal sensation, cdenia atid paiti are also ctitiitiioti symploms of stmbttrti (LIV dcrmatilis). Alletalions ha\c been observed iti cell iiopttlaliotis of the skin of paltetils sufferitig Itotii so-called "screen dertnalilis" sitiiilar lo those observed iti llie skiti damaucd due lo itllraviolel (L)V) lighl or ioni/itig tadialion. In "screen dertnalitis" patienls a tiiuch higher number of tnasl cells have bceti cibserxed. Il is known Ihal L'VB irradiation induces tnasl cell degtanulalion and tclease of TNF-K. The high nittiiber of tnasl cells prescnl in llic "setecti dertnalilis" palicnls atid the possible release of specilic substances, such as bistatnitie. may explaiti llieir elitiical sytnptonis of itch, paiti. edema and erythema. The tnost remarkable change among ctilancous cells, afler exposure wilh the above-metitiotieil itfadiatioti sources, is the disappearance of Ihe Latigerhatis" cells. This chatige lias also beeti obscr\ed iti "sereeti dertnalilis" patients, again pointing lo a common cellttkif atid tiiolecular basis. The results of this liletalute study detmnistrale lliat highly sitnilar changes exist in the skiti of "screen dertnalilis" palietils. as tegards the clitiical tnanifestalions as well as allcraliotis iti the cell popttlaliotis. atid in skin damaged by L'V lighl or ionizitig radialioti.