This is a personal topic since I have recently developed this skin condition, hence my knowledge about it (and sympathy to patients with skin conditions) has increased.
It most frequently occurs following a streptococcal throat infection (in my case) or after medications such as NSAIDS (ibuprofen) or B Blockers. This explanation is from Dermnet (a very good site for dermatology you can access through your mobiles):
Guttate psoriasis is psoriasis that is characterised by multiple small scaly plaques that tend to affect most of the body. ‘Gutta’ is Latin for drop; guttate psoriasis looks like a shower of red, scaly tear drops that have fallen down on the body. Lesions are usually concentrated around the trunk and upper arms and thighs. Face, ears and scalp are also commonly affected but the lesions may be very faint and quickly disappear in these areas. Occasionally there may be only a few scattered lesions in total.
The diagnosis of guttate psoriasis is made by the combination of history, clinical appearance of the rash, and evidence for preceding infection. It tends to affect children and young adults and has a good chance of spontaneously clearing completely.
Treatment options include: using emollients, steroid creams, coal tar or phototherapy.
On the drug list I note that aqueous lotion is available-this would be good as an emollient (although we have recently moved away from this in the UK due to some skin sensitivity to it). Patient should both wash with it, like a shower gel, and moisturise as much as possible.
Coal tar can also be applied but can be smelly, so moisturise after application. Steroids of any strength can be used but in my case it is too difficult to apply as I am completely covered in small spots.
I have been referred to hospital for phototherapy which is essentially UV exposure. Sun also works (but beware of sunburn), but isn’t so available in the UK even in summer!
Fingers crossed it works, as I’m very itchy