Isotretinoin, a Reaction History, and a Room With No Fan

Treat that history as a probable allergic contact dermatitis to acrylates, not as dry skin or a bad technician.

Reasoning:

• Itching and burning at the fingertips and peeling skin around the nails, recurring after each set, is the classic pattern of sensitization to (meth)acrylate monomers - often from uncured product touching skin, flooding the cuticle, or over-filing without dust control.
• Sensitization is generally permanent. Once sensitized, exposure to the same or cross-reacting acrylates can produce a worse reaction each time, including spreading rash.
• Do not proceed with the same liquid-and-powder chemistry. Do not run an in-salon "patch test" and use a clear result as permission - a single small exposure does not reliably predict a reaction, and a negative result does not make the service safe.
• Options: refer her to a dermatologist or allergist for assessment before any enhancement; if she declines, offer a service with no acrylate chemistry at all (traditional polish or a non-acrylate system) and explain the trade-offs.
• "The strongest monomer" is not a thing you should offer - it is a request to increase exposure to the exact chemistry that is probably causing her problem.

Both drugs thin and sensitize the skin and slow healing, so the plan changes from "normal manicure" to "minimal trauma."

• No cutting of live cuticle, no nipping hangnails, no aggressive pushing. Skin that is fragile tears, and a tear on a client on isotretinoin heals slowly and can become infected.
• No waxing, no exfoliating scrubs, no strong chemical exfoliants in a nail service on someone using topical tretinoin on the hands.
• Handle with care: gentle cleansing, soft pusher, cuticle oil, fine-grit shaping by hand. Avoid e-file work near the skin, which is also a dust and irritation source.
• Paraffin: skip or defer it. Heat plus a fragile, retinoid-thinned, possibly sensitized skin is a poor combination, and she already reports burning and peeling. If the skin were calm and intact, warm (not hot) paraffin at a lower temperature with a patch of intact skin would be the cautious version - but with this history, the defensible choice is to omit it and say why.
• Note the photosensitivity and mention daily sunscreen on the hands.

One sentence to her: "These products make your skin thinner and more reactive, so I'm going to do less to it, not more."

Ventilation and waste handling are part of the service, not housekeeping.

Before she sits down:

• Move her to the station nearest the door and the outside air path; keep the door open.
• Cover the trash with a lidded, lined container and empty it - used monomer-soaked paper towels off-gas into the room. Keep solvent waste in a closed metal container.
• Squeeze bottles closed when not dispensing; keep the dappen dish covered; keep product off the skin so you are not creating uncured monomer film on her fingers.
• Work smaller beads and dispense only what you need; the headache and eye irritation you feel at the end of the day are your own exposure signal, not a personality flaw.
• Ask about a proper local exhaust or downdraft at the source - that is the intervention that fixes both her exposure and yours.

Chemistry link: the monomer is volatile and a sensitizer; every open container and every smear on skin increases airborne concentration and her risk of the reaction she already described. The cheapest control is behavior (closed containers, no skin contact, small beads); the durable control is source-capture ventilation. If neither can be achieved, the honest answer is that a full liquid-and-powder service in this room is not a good plan for a client with her history.