What am I ill with? - Rash, pic included

[SealSong]

So after starting to feel ill yesterday I am feeling really ill today and had to ring in sick to work. Symptoms include weakness, general feeling of illness, bad stomach last night, sweaty, slight fever, headache and body aches.
Just spotted I have developed a rash also, it's just on my upper arms at the moment.
What could it be? I think I will ring the doctors, but don't feel well enough to actually go down there.

You poor thing

Looking back over what may have caused it, the only thing that stands out is cough medicine - robitussin, which has in its ingredients E123...google tells me this is banned in many countries and can produce a rash in some people. But I have no idea if I've ever had that e-number before, and not reacted to it.
Rash aside, I have had far too many illnesses in a short period of time, and the fact that the GPs want to investigate an underlying cause is worrying. It's good that they are investigating, but I'm dreading the results of the tests.

I wondered about scarlet fever too. We've had it twice here and I caught it mildly. It was hot and itchy. V sore throat too. But antibiotics should sort it out.

That does look like a scarlett fever rash and you do sound symptomatic of it too. Antib's should clear it up. Hope you feel better soon x

I had something very similar a couple of months ago. Felt bloody terrible, like I'd been hit by a bus, and had a painful, itchy rash - really sensitive to any sort of touch.

Doc said it was viral, other symptoms went after about a week, rash took about 2 weeks. Not sure why they are giving antibiotics for a virus though

Scarlet fever would fit, apart from I've not got a sore throat.

I had a rash like this after taking penicillin. It does look like a drug rash.

Scarlet fever rash leaves a clear ring around the mouth.

Have you been tested for coeliac?

My friend's children had a type of pneumonia that came with a rash. Chest X-Ray should hopefully figure that out

In fact it was a similar rash now that I think of it.

I have had a reaction like this with a drug allergy. It was worst on my upper arms, too, but spread nearly everywhere except my face. The culprit was penicillin.