What causes ichthyosis vulgaris?
Most people never notice the normal process of growing, dying and shedding skin. People with ichthyosis vulgaris either produce new skin cells faster than they can shed them, or produce skin at a normal rate but shed it much slower than normal. Either way, the result is a buildup of dry scaly skin that can look like fish scales.
If a child inherits the defective gene for ichthyosis vulgaris from one parent, they usually have a milder form of the disease. If the defective gene is inherited from both parents, the child will have a more severe form.
Although very rare, adults can develop acquired ichthyosis vulgaris when a disease or medication causes it. Triggering diseases include kidney failure, thyroid disease, sarcoidosis, some cancers, and infections such as human immunodeficiency virus (HIV) AIDS or leprosy.
Ichthyosis can also be triggered by medications or vitamins, although this is very rare. Triggering medications include Cimetidine (used to treat ulcers and acid reflux), Clofazimine (treats leprosy), or nicotinic acid, one of the B vitamins.
Acquired ichthyosis can develop before there are symptoms of the triggering disease. The person should have a complete physical exam to find the cause if this happens.