Not at all! I have had lots of facials and manicures and whatnot, and the techs who work on me see me as an interesting new challenge.
I am careful to explain my condition, but you must remember most of these techs have been to school and studied skin and diseases of the skin and nails, and are more accepting of ichthyosis than most of the health professionals I have dealt with!
Once they know what it is, and what things have helped or hurt your skin, they are usually quite eager to try out new products or techniques.
I have had several Adrian Arpel facials, and they have some interesting vegetable products that you massage into your skin, and keep massaging in until it turns dry and basically sloughs off the skin. I don't bother to buy the product since it works so much better when someone else does it, so I just go in and let the consultants work on me.
By all means, get a facial, talk to a manicurist, and don't deprive yourself of some pampering!