I don't have EHK and cannot offer any advise that may be particular to that condition, such as whether a particular topical treatment is good or not. Someone like Keith C would be able to do that. I also don't know what part of the country your brother lives in, and what kind of work he does, meaning does it snow in the winter and does he have to work in air-conditioning?
I ask because in general ichthyosis is highly affected by the climate the patient lives in. But there is a lot of misunderstanding surrounding that. Vulgaris, for example, is greatly subject to seasonal variation, good in summer, bad in winter. Please see my other postings. Others are less subject to seasonal variation, so I am told. I consider the threshold of severity of a condition to be "heat intolerance." Does the patient have a problem breaking a sweat because the scales are blocking the pores?
I would find out from your brother if he has this problem first. For me, this is the biggest issue to be addressed, more so than the aesthetic and cosmetic concerns and social implications. It can affect how and where a person can best earn a living and what career paths may be open.
For me, with severe vulgaris, where I choose to live and work can greatly affect the appearence of my skin condition, and thereby, my social life. In general, the more time I could spend in hot and humid weather and away from air-conditioning, the better off I would be because the climate facilitate sweating which in turn facilitate clearing the scales.
Other people have posted that they feel more comfortable in a mildly cool climate, such as the Pacific Northwest. If the condition you have is such that the scales cannot be improved by a tropical climate or summer, then by all means you should live in a mildly cool climate (but not a cold one that aggravates the scales).
Find out from your brother whether his scales improve during the summer. If they do, his best bet is to relocate to some place like South Florida. Good luck.
Don't ever lose hope when
there is a promised land, and "sweat" dreams