Nevus of Ota is a grey-blue or brown spot on one side of the face (around the eye, temple, cheek or nose), sometimes also in the white of the eye. Nevus of Hori, its neighbour, forms brown-grey spots on both cheeks that appear in adulthood and are often mistaken for melasma. These are benign anomalies of deep pigmentation, which do not go away with creams. In Marrakech, Dr Sara Zahid, a dermatologist in Guéliz, makes the diagnosis and offers treatment with a Q-Switch and picosecond laser (StarWalker MaQX), over several sessions.
Clinical case of Dr Sara Zahid: before / after laser, published with the patient’s consent.
A bluish, grey or brown pigmentation, due to pigment cells located in the deep dermis. It generally affects one side of the face, in the area of the eye, temple, cheek, forehead or nose, and may reach the white of the eye. It is present at birth or appears in childhood or adolescence, and is more common in dark and Asian skin. It is benign, but does not disappear on its own.
Nevus of Hori (or acquired Ota-type nevus) shows as small brown-grey spots, often on both sides of the cheekbones, appearing in adulthood, more often in women. It looks like melasma, with which it is frequently confused, but does not respond to melasma treatments. Only a dermatological examination, sometimes with dermoscopy, can tell them apart: hence the value of consulting before piling on creams and peels.
The pigment lies in the deep dermis, beneath the layer that lightening creams reach. Depigmenting products and superficial peels therefore have little effect, and some can irritate the skin. Lasers with very short pulses, which pass through the surface and break up the deep pigment, are the reference treatment.
The clinic has the StarWalker MaQX laser, which combines Q-Switch and picosecond pulses across two wavelengths (1064 and 585 nm). The laser passes through the epidermis without damaging it and breaks up the pigment in the dermis, which immune cells then clear. The choice of wavelength and settings depends on the depth of the pigment, the colour of the spot and the skin type.
Several sessions are needed, often more than five, spaced several weeks apart (generally one to three months), to let the skin recover. Improvement is gradual: the spot lightens, sometimes markedly, sometimes without total disappearance. The result varies with the depth of pigment, the area and the skin; comparison photos allow progress to be followed. Improvement is assessed with you, session after session.
In olive and dark skin, where these nevi are common, the laser can cause a temporary brown mark (post-inflammatory hyperpigmentation) or, more rarely, a light mark if badly set. Dr Zahid is trained in dark skin types: cautious settings, longer intervals, strict sun protection, skin preparation, and a test on a small area if needed.
When a nevus of Ota affects the white of the eye, follow-up by an ophthalmologist is advised, as it can come with pigmentation of the eye and, rarely, raised eye pressure. This monitoring is independent of skin treatment and the dermatologist refers you.
Avoid sun and UV before and after sessions and apply sunscreen. Laser is postponed in case of tanned or damaged skin, pregnancy or a tendency to keloid scars; report photosensitising treatments. After a session, the skin is red for a few hours to a few days, sometimes with small scabs.
A brown or grey spot on the face is not always benign: a nevus of Ota, a nevus of Hori, melasma, a lentigo or, more rarely, a lesion to monitor are treated differently. The dermatologist examines the spot, with dermoscopy if needed, before any laser; it is not a comfort treatment but a medical procedure.
At the Skin & Aesthetic Clinic, in Guéliz, with Dr Sara Zahid, dermatologist, by appointment, in French, English or Arabic. A consultation precedes the first session; a detailed quote is given before any procedure, with no single displayed price.
A bluish, grey or brown spot on one side of the face (eye, temple, cheek, nose), due to pigment in the deep dermis. It is benign but does not disappear on its own.
Nevus of Ota is generally on one side of the face, present from childhood or adolescence. Nevus of Hori forms brown-grey spots on both cheeks, appearing in adulthood.
No, but they look alike and are often confused. Melasma is superficial and responds to depigmenting treatments; nevus of Hori is deep and needs a laser.
It is benign in the great majority of cases. Involvement of the white of the eye warrants ophthalmological follow-up; any change (relief, colour, bleeding) should be shown.
Q-Switch and picosecond lasers, like the clinic's StarWalker MaQX, which break up the deep pigment.
Several, often more than five, spaced several weeks apart. The number depends on the depth of the pigment and the skin's response.
The sensation is described as small rubber-band snaps; cooling and an anaesthetic cream can be used. Sessions are short.
Yes, with cautious settings, longer intervals and strict sun protection, to limit the risk of a brown or light mark. Dr Sara Zahid is trained in dark skin types.
They have very little effect, as the pigment is deep. They can even irritate the skin: it is better to consult before piling them on.
No, as a precaution: laser is postponed during pregnancy.
The price is given by the clinic after the consultation, as it depends on the surface and number of sessions. A detailed quote is given before any procedure; there is no single displayed price.
At the Skin & Aesthetic Clinic, in Guéliz, with Dr Sara Zahid, dermatologist, by appointment, in French, English or Arabic.
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