Should an increase in petechiae be looked into when on hydrocortisone (cortef) tablets? have had some for years but they are increasing in numbers.

Absolutely: I am going to assume that your health is stable and that you are not thrombocytopenic. If you actually have petechiae, they always deserve to be worked up; you want to know whether you have a capillary fragility syndrome. In the US, we have food faddists who give themselves scurvy; I trust Australians are more sensible. Cortef (hydrocortisone) makes capillaries more fragile. I'd get specialist consultation.