Let's start by explaining that I do not want confusion with PVC (soft plastics)

I have had a conversation with an employee who believes that contact with PVCu during the manufacturing process is causing  their contact dermatitis. There are no other chemicals involved in the process (not even water). Any contact would be with the hard profiles, and a small amount of swarf, with LEV taking the majority away. The factory is well ventilated. 

I have never found any mention of WELs relating to PVCu (although I usually go with the standard polyvinyl chloride standards for dust, as this seems a good starter point @ 10/4 mg³ inhalable/respiritable). As far as I am aware PVCu is one of the most inert substances known to man, hence the widespread use, and the problem with plastics in the world. it would need cooncetrations of sulphuric acid > 90% or nitric acid > 50% to disolve it. In fact if I were to put gloves on this person (and to be fair the issues are on their forearms and knees) they would have more exposure to plastics, not less.

The data sheet is as useful as ever, basically an empty sheet, with the only control being gloves to avoid sharp edges.

Am I missing something?

Yes A Kurdziel, that is exactly what I mean. The only method I would be aware of to suspect it causing CD is if there were friction and sweat involved, this is not the case. Basically it is sawing lengths of PVCu (hard plastic), at room temperture, within an enclosed machine. The only handling is placing the hard PVCu onto the machine, and removing it from the machine, at a rate of around 20-30 cuts per hour.

The machine has LEV to remove the majority of the swarf (dust), more of a house keeping control than an exposure control, due to the reasons given above. However there is often a small amount of dust trapped within the profile when removing them from the machine, which is tipped into a bin.

I am confident we don't have a "claim" to answer for here, but I am concerned that there is something more I could be doing to help the person. Their actual diagnosis is Psoriasis, but they are adament this is not the case, even though they had the condition when they joined the company 12 years previous. They are claiming the PVCu is worsening the condition.

We are a small company, so a trip to occupational health is probably not an option.

send the person for a test it will identfiy whether they are or are not...I had one very similar last week turns out his wife changed the washing powder

As AK states, psoriasis is a genetic problem. One of the common triggers is stress. The locations described are common areas on the body where the psoriasis makes itself apparent. One of the common triggers is stress, other are light, medication, infection but it seems that the exact cause is often difficult to determine with any certainty and could be a multiple causation. Quoting P K Buxton in his ABC of Dermatology: "The cause is unkown and the best answer is that the tendendcy to develop psoriasis is part of a person's constitution and some factor triggers the development of the clinical lesions. Known factors include physical or emotional stress, local trauma to the skin, infection, drugs." Note that there is more than one type of psoriasis and the appearances can vary. The fact that they have already had psoriasis suggests that they have a genetic tendency to develop this, but what triggered the present outbreak may be impossible to determine with any certainty. GP should be able to prescribe a treatment.

 ...you know this is a carcinogen and has been linked to HCC liver cancers...you need to move this to private now I think you have enough from here to say test and investigate as workplace if it isn't then good news either way this persons needs your help in getting sorted...