Problems after Laser Hair Removal: Increased Hair Growth, Folliculitis, Pigmentation, Eye Safety — What Can Be Done?

What problems can occur after laser hair removal?

Laser and intense pulsed light (IPL) devices work by the pigment in the hair root absorbing light and converting it into heat. For how the procedure is done, who it suits and realistic expectations, see our article “Laser Hair Removal”. This article focuses on the problems that can arise after the procedure.

A recent review examining side effects states that problems are mostly related to skin type, the area treated, the device and the settings. In other words, the same procedure can carry very different risks in different people and under different conditions. For this reason, having the device and settings appropriate for you determined by examination is the basic step in preventing problems.

How long do redness and bumps around the hair follicles last?

Immediately after the procedure, redness, mild swelling, a feeling of heat and small bumps around the hair follicles are common. The American Academy of Dermatology (AAD) states that the most common side effects are mild and last one to three days. These symptoms should lessen a little each day.

Redness, pain, blistering or discharge that increases rather than lessens as the days go by is outside the expected course and requires a physician’s assessment.

Hair increased instead of decreasing: what is paradoxical hair growth?

Paradoxical hair growth (paradoxical hypertrichosis) is hair increasing, thickening or darkening, instead of decreasing, in the area treated with laser or IPL or immediately around it. It is not a burn or a disease and is not an emergency; however, it is upsetting because it is the exact opposite of the result expected.

In a systematic review bringing together 22 studies covering about 9,700 patients, the average frequency of this condition was calculated at about 3 per cent. However, the results of the studies differ greatly from one another; for this reason this figure should be read not as a precise rate but as a rough estimate. The great majority of cases occurred on the face and neck, and it was reported very rarely outside these areas.

In the same review, the type of device used and the interval between sessions were not seen to change the frequency; the data were found insufficient to assess the effect of sex and skin type. In some studies it has been reported more often with fine hair and in darker skin. Why it occurs is not fully known.

If you notice this, tell your physician. In most of the studies examined, the increase in hair gradually lessened when treatment was continued; however, how the treatment plan should be changed is decided by the physician, who assesses your skin and hair type. In women with new or rapidly increasing hair growth on the face, whether there is a hormonal cause should also be investigated separately.

What causes folliculitis and an acne-like rash?

Folliculitis is inflammation of the hair follicles. After laser it can arise from heat-related irritation, sweating, friction or bacteria on the skin settling in the hair follicle. It appears as red bumps around the hair follicles, sometimes white-tipped, itchy or mildly painful. It is noticed more often in areas with thick hair that are exposed to friction, such as the back, chest, legs and bikini area.

The bumps around the hair follicles that are seen immediately after the procedure and settle within a day or two are not folliculitis; they are the expected response produced by heat in the hair follicle. Bumps that appear days later, increase in number, are filled with pus or are painful, on the other hand, should be shown to a physician. You can find in detail which symptoms suggest infection in our article “Infection after Aesthetic Treatments”.

Can the skin darken or lighten?

It can. Light is absorbed not only by the pigment in the hair root but also by the pigment in the skin. For this reason the risk of darkening (hyperpigmentation) or lightening (hypopigmentation) is higher in darker skin and in skin that is tanned or has recently been exposed to the sun. The AAD states that most of these colour changes improve over time, while some may not reverse.

If you notice a change in colour, protect the area strictly from the sun and show it to your physician. Do not use skin-lightening products on your own. For the general causes of pigmentation and the treatment options, see our article “Dark Spots and Melasma”.

What if there is a burn and blistering?

Blistering, a grey-white colour, crusting or marks in the shape of the device handpiece may be signs of a burn and require you to contact a physician the same day. We have dealt in detail with the causes of burns, what to do straight away, and the pigmentation and scarring that may develop afterwards in our article “Burns and Pigmentation Changes after Laser and IPL”; we do not repeat it here.

Can laser hair removal harm the eyes?

Yes, it can if the eyes are not protected. The coloured part of the eye (the iris) and the retina also contain pigment and absorb laser light. In the medical literature, damage such as inflammation inside the eye (uveitis), thinning and distortion of the iris, an irregular pupil and cataract has been reported after laser hair reduction. A significant proportion of these reports relate to treatments around the eyebrows and eyes.

In a review examining 21 published cases of eye injury in cosmetic laser procedures on the face, eye protection was not used at all, or was removed during the procedure, in more than 60 per cent of cases. In about a third, injury occurred even though protection was used. For this reason, treatments close to the eye area call for particular care and experience even when goggles are worn.

• Everyone in the treatment room must wear protective goggles suited to the wavelength of the device being used.
• Do not take the goggles off until the procedure is finished; if you feel they have slipped or that light is leaking in, ask for the procedure to be stopped.
• Laser hair removal is generally not recommended for areas very close to the eye, such as the lower part of the eyebrow and the eyelid; discuss other options for these areas with your physician.
• Covering your eye with your finger or with cotton wool is not adequate protection.

The signs of eye damage are eye pain, redness, extreme sensitivity to light, blurred vision, a spot in the field of vision and a change in the shape of the pupil. In some of the cases reported, the symptoms were noticed hours, or even a day or two, after the procedure. If you have any of these symptoms, do not wait.

What happens if a pulse is fired over a mole or a tattoo?

Moles and tattoo ink contain dense pigment and absorb light strongly. A pulse fired over a tattoo or over eyebrow, lip or eyeliner pigmentation (micropigmentation) can cause a burn and blistering at that point and spoil the colour of the tattoo. For this reason tattooed areas are skipped or protected by covering them.

In a systematic review examining the studies on moles, shrinkage of moles, lightening or darkening of their colour, their shape becoming asymmetrical and changes in their dermoscopic appearance were reported after laser hair removal. These changes could begin about two weeks after the procedure and last for years. The same review stated that there was no documented case of a mole turning into cancer after laser hair removal; however, long-term follow-up data are limited.

The real problem is this: a mole whose appearance has changed becomes harder to assess in the future, and a genuine warning sign may be missed. For this reason it is recommended that moles be protected during the procedure, and that moles changing in shape or colour be shown to a dermatologist before hair removal. We have dealt with the relationship between laser hair removal and cancer in a separate article in our rumour series.

Does laser hair removal trigger cold sores?

It can. A cold sore arises when the herpes simplex virus, which lies dormant in the body, is reactivated. The heat and tissue irritation of laser treatments on the upper lip, chin and face can lead to a flare-up in people with a history of cold sores. The AAD lists a cold sore flare-up among the uncommon side effects of laser hair removal. There are no reliable data on how often cold sore flare-ups occur after aesthetic procedures.

A cold sore usually begins in the days following the procedure with a tingling or burning sensation; small, fluid-filled blisters then appear in clusters. This appearance can be confused with a burn or a bacterial infection, which is why it is important for your physician to see it. If you have a history of cold sores, say so before the procedure; your physician will decide whether preventive treatment is needed. No procedure is carried out on an area with an active cold sore.

Normal, consult a physician, or an emergency?

What can your physician do?

The physician first examines the area and asks when the procedure was done, with which device and at what settings, when you were last in the sun and which medicines you take. Depending on the situation, the following approaches may be considered:

• For expected side effects: monitoring, soothing care and advice on sun protection.
• Where folliculitis or infection is suspected: taking a sample if necessary, and treatment chosen by the physician.
• For a cold sore flare-up: considering a treatment effective against the virus, and a preventive plan for later sessions.
• For a change in colour: strict sun protection, monitoring and, where necessary, treatments recommended by the physician; postponing any new session on that area until the problem has resolved.
• For paradoxical hair growth: reviewing the treatment plan — changing the device, the settings or the method and, if necessary, investigating hormonal causes.
• For eye symptoms: referral for an urgent eye examination.
• For a mole whose appearance has changed: dermoscopic assessment and, if necessary, further investigation.

For the general steps you can follow when you have a problem, our article “What Should You Do If a Complication Occurs after an Aesthetic Treatment” may be a useful guide.

What can you do at home, and what should you not do?

• Follow the aftercare instructions your physician gives you; keep the area clean and choose loose clothing that reduces friction.
• Protect the area from the sun; on exposed areas, use the sunscreen recommended by your physician regularly.
• For the period your physician recommends, avoid hot showers, saunas, Turkish baths, swimming pools and exercise that makes you sweat heavily.
• Record changes with dated photographs; note the date of the procedure and where it was done.

Do not do the following:

• Do not squeeze or burst the bumps; do not pick off crusts.
• Do not use antibiotic, corticosteroid or skin-lightening creams on your own.
• Do not wax or use an epilator, an exfoliating mitt (kese), peels or acid-containing products until the area has healed.
• Do not remove the increased hair with tweezers or wax; only shave until you have spoken to your physician.
• If you have an eye symptom, do not wait thinking 'it will pass'; do not rub your eye, and do not use eye drops on your own.

To reduce the risk

• Ask for your skin type and hair type to be assessed before the procedure; ask whether a test pulse will be carried out on a small area at the first session.
• In the weeks before and after the procedure, do not sunbathe, use sunbeds or use tanning products.
• Mention your history of cold sores, the medicines and herbal products you use, any tendency to scarring and any hormonal problems.
• Show the practitioner your moles, your tattoos and any eyebrow or lip pigmentation; ask how these areas will be protected.
• Confirm that the protective goggles are suited to the device and will stay on throughout the procedure; do not agree to treatment of areas very close to the eye.
• For fine, light-coloured hair on the face and neck, discuss in advance whether the procedure is really suitable and the possibility of increased hair growth.
• If during the procedure you feel a sharp pain that is different from what was expected, or light in your eye, say so immediately.

When choosing where to have the treatment, our article “A 10-Point Safety Checklist for Choosing a Clinic and Physician for Medical Aesthetics” may be useful to you.

Where is scientific knowledge limited?

Most of the studies on the side effects of laser hair removal are retrospective and observational; the devices, settings and patient groups differ greatly from one another. The rate of about 3 per cent given for paradoxical hair growth is the average of studies whose results do not agree with one another, and it does not show the risk specific to you. Eye injuries and changes in moles, meanwhile, are known largely from case reports; their true frequency is not known. Nor are there reliable data on the frequency of cold sore flare-ups. The information in this article may be updated as new data arrive; this page is for information and does not replace an examination.