For GPs: when to refer
scar, filler and laser issues

Which presentations does Dr Sin Yong assess?

Four groups of referral are a good fit. The first is atrophic acne scarring, ice-pick, boxcar, rolling and tethered scars, in a patient whose acne is controlled or close to it, because active inflammation is settled before any scar work begins. Scar type is mapped and matched to subcision, TCA CROSS, fractional CO2 resurfacing, RF microneedling or collagen stimulation, as the acne scar treatment page sets out. Flat red or brown marks after acne are pigment rather than scar and are managed differently.

The second is the patient who has had filler elsewhere and is worried about it: a firm or tender nodule, product that appears to have moved, a face that looks over-filled, or a late inflammatory lump months or years after injection. Dr Sin Yong maps existing filler with ultrasound before deciding whether to dissolve, manage or wait; hyaluronidase acts on hyaluronic acid only, so Sculptra, Ellansé and Radiesse are managed case by case. Filler correction describes the approach, and a second opinion is available where the patient simply wants another doctor to look.

The third is pigment change after a laser, peel or energy treatment done elsewhere: post-inflammatory hyperpigmentation, which is common in Fitzpatrick III to V skin, and the less common hypopigmentation, where the question is whether melanocytes are suppressed or lost. The fourth is pattern hair loss in men and women, assessed with a scalp examination and blood tests before anything is proposed; medical therapy is the foundation, and where follicles are already lost, transplantation is referred to an appropriate surgical specialist.

Which cases are urgent, and how are they handled?

Suspected vascular occlusion after filler is seen the same day during clinic hours. The signs are skin that blanches white or turns dusky, purple or mottled near the injected area, often following the territory of an artery rather than the needle entry, and pain that is severe or getting worse rather than settling. If you have a patient in front of you with these signs, telephone or message +65 8023 7170 rather than writing a letter, and send the patient directly; the line is answered Monday to Friday 10am to 8pm and Saturday 11am to 3pm. Hyaluronidase is kept wherever hyaluronic acid filler is injected, and published guidance describes a high-dose, repeated protocol for occlusion from hyaluronic acid.

Some signs bypass the clinic altogether. Any change in vision after filler, eye pain, new facial weakness, slurred speech or limb weakness, and swelling of the lips, tongue or throat with difficulty breathing need the nearest hospital emergency department or 995, because the imaging and the other specialities that may be needed are there. Outside clinic hours, blanching and worsening pain also go to an emergency department rather than waiting for the clinic to open. The complication care page and the vascular occlusion warning signs page set out the same sequence for patients.

Everything else is routine and can be booked in the usual way. A nodule that is stable, filler that looks heavy, pigment that has darkened after a laser and hair thinning are assessed at a scheduled consultation, and the patient is not disadvantaged by waiting for one. If you are unsure which category a presentation falls into, the safe assumption for white, mottled or increasingly painful skin after filler is that it is the urgent one.

“Hyaluronidase dissolves hyaluronic acid and nothing else. If someone offers to dissolve Ellanse or Sculptra, they are describing something that does not happen.”

Dr Sin YongOn what hyaluronidase can and cannot reverse

What should you send with the referral?

A short letter is enough, and the patient can bring it or you can email it to dr.sinyong@gmail.com. The useful content is the presentation and its timeline, what was injected or which device was used if known, with product names, dates and the treating clinic, and what has been tried since. For filler concerns the product matters more than anything else, because only hyaluronic acid can be dissolved; if the patient does not know, say so and the assessment proceeds with ultrasound.

Please include the medication list, in particular isotretinoin past or present, anticoagulants and antiplatelets, photosensitising drugs and any immunosuppression, and relevant history: pregnancy or breastfeeding, a tendency to keloid or hypertrophic scarring, previous reactions to filler, anaesthetic or hyaluronidase, cold sores, and implanted electronic devices or metal in the field, which change which energy devices can be used. Any photographs you have taken for your own record are helpful for comparison; they are not required.

The patient then messages the clinic on WhatsApp at +65 8023 7170 mentioning the referral, or you can message on their behalf, and the right length of appointment is booked. Photographs over messaging platforms are not needed before the visit, because the assessment is done in person. The consultation process page describes the steps the patient will go through.

What does he not treat, and where does it go instead?

Dr Sin Yong is an aesthetic physician registered with the Singapore Medical Council; he is not an accredited dermatologist or plastic surgery specialist, and he refers rather than stretches. Surgery is referred to a plastic surgery specialist: scar revision or excision, blepharoplasty, hair transplantation and the removal of skin excess that no energy device reaches. Where surgery is the realistic tool, the letter back to you will say so rather than proposing a non-surgical alternative that cannot do the job.

Dermatological disease goes back to dermatology. A changing or atypical pigmented lesion, an undiagnosed rash, vitiligo that is spreading, severe or nodulocystic acne needing systemic therapy and monitoring, and scarring alopecia or alopecia areata that needs immunomodulation are outside what this practice should be managing alone. Where a patient arrives with one of these, you will hear about it, with a suggested route.

Within scope, some patients are told to wait. Recently injected filler often looks worse in the first weeks than it will settle to, active acne is controlled before scar work, a recent tan defers laser, and melasma that flares with heat is kept away from energy devices. Advising no treatment is a normal outcome, and it is written in the letter like any other.

What happens at the assessment, step by step?

The consultation is conducted by Dr Sin Yong personally. It begins with the history, including your letter, then examination at rest and in movement, in the light and at the angles that show what is happening in the tissue. For filler, ultrasound is used to see where product sits and at what depth, so that any hyaluronidase is directed at the product rather than guessed at. For scars, each scar is classified by type and depth; for pigment, by level; for hair, the pattern is staged and blood tests reviewed or requested.

The patient is given the findings and the realistic options, including what each can and cannot do, the risks, and what no treatment would mean, and any plan is written down with the product or platform, the order and the review. The patient is not expected to decide on the day. Treatment, where it follows, is performed by Dr Sin Yong himself and not delegated, and written aftercare lists the signs to report.

Fees are quoted in writing after the examination, never before, and Singapore's rules prevent prices being advertised, so none are given here. The consultation carries its own fee, stated when the patient books. What moves a treatment fee is the area, what the assessment finds, which product or device is proposed and how much of it, whether approaches are combined, and how the plan is staged; the how fees are quoted page lists the factors. The practice offers no incentives for referrals.

How is the patient returned to you?

Every referred patient goes back with a letter. It records the findings, including the ultrasound picture where filler was mapped, what was advised, what was done and with which product or device, the review arranged, and what to watch for and when to send the patient back. Where a complication was managed, the letter says what was given and when, so that your record is complete.

If the patient is referred onward, to dermatology or to a plastic surgery specialist, the letter to you says so and gives the reason. Nothing on this page or in the clinic is a comment on the doctor who treated the patient previously: findings are described, and the people behind them are not judged, in line with the SMC ethical code. Background on Dr Sin Yong's qualifications is on the About page, and clinical questions about a referral can be put to him directly on +65 8023 7170 during clinic hours.