Striae
Also known as stretch marks, striae rubra (red stretch marks), striae alba (white stretch marks)
What is striae?
Stretch marks are extremely common, affecting over 70% of the population. There are two types of stretch marks – striae rubra (red or new stretch marks) and striae alba (white or old stretch marks). New stretch marks are more responsive to treatment than old stretch marks.
What causes striae?
Stretch marks, as the name suggests, are due to stretching of the skin, which results in altered structural support in the deeper layers of the skin. Microscopic studies of stretch marks show alteration in collagen and diminished elastin, as well as dermal oedema (swelling). Early stretch marks exhibit an increase in the number of blood vessels and inflammation, resulting in pink-purple discolouration.
What do striae look like?
The first signs of stretch marks are pink to purple lines usually running crosswise on the trunk and lengthwise along the limb. Early stretch marks may be itchy. Over time stretch marks lighten and develop a pale, wrinkled appearance known as striae alba.
Stretch marks most commonly occur on the abdomen, inner arms, the back and breast areas. Stretch marks may also develop in the groin and armpits if high strength steroid creams are inappropriately used in these areas.
What other problems can occur with striae?
- Puberty and weight gain: Weight lifters often develop stretch marks on the arms. In puberty, stretch marks may occur on the back, abdominal areas and breasts.
- Pregnancy: Stretch marks most commonly develop in the third trimester of pregnancy. This is thought to be caused by hormonal changes and weight gain associated with pregnancy.
- Medications: Corticosteroids creams, ointments or tablets may cause stretch marks if used inappropriately and without dermatologist supervision.
- Diseases: Cushing’s syndrome, Marfan’s syndrome or Ehlers-Danlos syndrome can predispose a person to developing stretch marks.
How are striae diagnosed?
Stretch marks most often occur in otherwise normal individuals and no investigations are needed to make a diagnosis. Stretch marks may occur in people who have Cushing’s, Marfan’s or Ehlers-Danlos syndromes. Investigations are determined from clinical examination.
How is striae treated?
Stretch marks are a cosmetic problem and treatment is optional. The majority of stretch marks will fade over time. Early red stretch marks respond better to treatment than older, white stretch marks. No treatment will remove stretch marks completely.
Treatment of red stretch marks
- Pulse dye laser. This is the most promising method of treating early red stretch marks and may help decrease the red discolouration in stretch marks. Most people will benefit from three to five treatments, spaced 2 to 4 weeks apart. This treatment can cause temporary bruising.
- Vitamin A creams such as tretinoin can be combined with laser treatments to treat stretch marks.
- Fractional non-ablative lasers can improve early stretch marks. At best, this treatment will help to blend the affected and unaffected areas, potentially making them less visible. Three to five treatments are needed for best results.
Treatment of white stretch marks
White stretch marks can be very difficult to treat. Expect only a mild to modest improvement with multiple sessions. Treatment methods include:
- Lasers. In old stretch marks, both fractional ablative and non-ablative lasers are more effective than pulse dye lasers. Fractional lasers work by stimulating and remodeling collagen and elastin. At best, this treatment will help to blend the affected and unaffected areas, potentially making them less visible. Three to five treatments may be needed to see some improvement.
- Skin needling is a form of fractional skin treatment. Success with this treatment is highly variable.
- Prescription vitamin A creams such as tretinoin may be partially effective.
- Vitamin E creams and various oils have not been scientifically proven to reduce stretch marks. However, they may be worth trialing.
What is the likely outcome of striae?
The majority of stretch marks will improve over time, changing colour from red-purple to pink, then finally achieving a white wrinkled appearance.
Treating early stretch marks with laser treatment combined with vitamin A creams gives the best outcome.
This information has been written by Dr Davin S Lim and Dr Philip S Bekhor