If it's on both eyes you have probably been sensitised to the glue. If it goes away quickly then you have been sensitised to the solvent in the glue if it persists it's the glue itself and you should remove them as soon as possible. It is not common to develop a reaction to the adhesive if your patch test was clear but it can happen even after years of wearing lashes.
Another possible cause if it's on both eyes is an infection caused by not sterilising the tweezers fully or not disinfecting hands. This should not prevent further treatment if it is caught quickly and treated by your Doctor.
Once sensitised it's unlikely that you will be able to have this treatment without further reaction, no matter which brand of glue that you use. Uncontrolled glues are more likely to cause this so it's safer to use medical grade glues (ISO 10993-5) that have been tested to not cause cell damage, even these glues can cause sensitisation if misused. Technicians that attempt to save money by using glues of questionable origin sometime don't realise the damage they are doing, not only to their clients, but to their long term business .
If it's on one eye then the lash follicle or the glands at the base of the lash have been blocked, again remove as soon as possible. Once healed you should have no problem with further treatment but you run an increased risk of becoming sensitised so please take extra care and ensure that your therapist takes time to ensure you have the required safety distance. This can be the cause on both eyes if the lashes have been applied too close to the follicle or touching the skin of the eyelid but you said that the same tech had applied before with no problem so it's unlikely.
In both cases you must contact the technician that applied the lashes and if the condition is not rapidly improving on it's own; immediately seek the advice of a health professional.
