Test for Handedness

of depth of ingrained dirt, or tattoo pigment, also affects the proper choice of technique. Depth can sometimes only be assessed accurately during the course of planing through the affected area of skiin. It not infrequently happens that the whole depth of skin has to be removed. The operator then has to make a decision whether to use a surgical method of closure or to allow healing by marginal ingrowth with a risk of keloid or other formation of gross unsightly scarring. Clearly choice of method and end result will be influenced by training of the operator in use of local flaps and other plastic methods. It is for these reasons that I would plead that the method be used only under full operating theatre conditions, not in the inadequate arrangements of consulting-rooms. It also seems reasonable to plead that whoever uses this method should be ab!e to supplement it by other plastic techniques, such as ridectomy, when these are necessary for the best standard of result, or when complete abrasion of the lesion or pigment leaves a skin defect. The use of " freon "' and other freezing agents as the anaesthetic also raises important points for debate. Freezing5 causes intracellular dermal rupture; and Pomerat and Lewis' have shown by tissue culture methods the added burden that this causes to normal healing. Nor do English patients take well to the freezing of large areas of the face; nor can it be considered really safe for use near the eyes. For these and other reasons I prefer local analgesia; a general anaesthetic is preferable for the most extensive cases. There are also reasonable matters for debate about almost every aspect of the abrasive techniques at present used; about type of abrasive wheel, about rate of revolutions per minute of the wheel (the faster rates probably cause loading of the wheel more quickly, causing thermal friction to the tissues rather than abrasion), and about the type of post-operative dressing, as well as about the range and scope of method. My own view is that dermabrasion is capable of dramatically successful results in a minority of patients (such as with small superficial angiomata), and can give a very reasonable margin of improvement to many other patients (such as girls with acne scars, provided it is repeated two or three times); but it must also be remembered that it can be harmful and has some special complications of its own. This especially holds if it is not. used with technical skill. While minor areas can be successfully abraded under local analgesia on an out-patient basis, extensive facial operations can, I believe, only be safely done under general anaesthesia in an operating theatre with adequate postoperative nursing as an in-patient for two or three days. If these precautions are not observed, the method is likely to fall into the disrepute in England that prevails for it in many parts of America.-I am, etc., London, W.1 PATRICK CLARKSON.