Thanks for the information.
The symptoms that you are describing do seem like an allergic reaction. It does not seem like an infection. The fact that your co-worker is also having the same symptoms indicates that the causative factor or the allergen is in the work place. This can be in the form of a room spray, dust mites, pollens (if there is vegetation around your office) etc. Rarely, the exact cause cannot be found. Also, since you do respond to hydrocortisone, though temporarily, indicates that this is most probably an allergic reaction. Since you have tried most of the over the counter medicines, I would recommend you to consult a Dermatologist for a first hand examination. You might need a longer treatment of hydrocortisone 1% or other milder steroid with slow tapering off of the ointment to prevent recurrence.