Striae

1 - ACKNOWLEDGEMENTS

Chapter written with the help of the EADV, the Fondation René Touraine and the Therapeutics in Dermatology

2 - OVERVIEW

Striae, also commonly known as “stretch marks”, are lines that appear on the skin as a result of tearing of the underlying tissue due to over-stretching or rapid growth. This is a common, benign condition, but one that can be cosmetically bothersome.

There are mainly two different types of striae: “striae rubra” (red) and “striae alba” (white). Also, striae that develop during or after pregnancy are called “striae gravidarum”.

3 - SIGNS AND SYMPTOMS

Striae usually present clinically as 1-10mm-wide skin lines, measuring up to several centimetres. They are most often multiple and tend to have a symmetrical distribution. Stretch marks most often occur in body sites where the skin is subjected to increased stretching, like the abdomen, breasts, buttocks, thighs, arms and lower back. Steroid-related striae (e.g.: corticosteroid therapy; Cushing syndrome) can be wider, larger and widely distributed, possibly affecting other skin sites.

 “Striae rubra”, which are the first presentation of stretch marks, can be pink to red to violaceous in colour. Over several months, they evolve into “striae alba”, by lightening into white or flesh-coloured, scar-like lines of thinned and depressed skin, that are persistent and can worsen with aging. In dark-skinned people, striae may be grey-black or bluish in colour.

Although recent striae can be slightly itchy, these skin lesions are typically asymptomatic. They can, however, cause psychological distress, particularly if very pronounced or disfiguring.

4 - WHO GETS AND CAUSES

Resulting from mechanical stress forces on the skin caused by fast or progressive tissue over-stretching, stretch marks are very common, particularly among:

• Adolescents, during or after growth spurts (girls more often than boys)
• Pregnant women (mostly in 2^nd / 3^rd trimester)
• Overweight or obese people
• People who suddenly gain or lose weight
• Weightlifters and body-builders
• People undergoing certain surgical procedures (e.g.: breast augmentation)

Family history is also a risk factor for development of striae.

Striae can also be caused by some drugs, especially oral and topical corticosteroids used for prolonged treatment periods, or anabolic steroids.

Finally, striae can be skin manifestations of internal diseases, like Cushing syndrome (excessive levels of circulating cortisol) and Marfan syndrome (genetic disorder affecting the connective tissue).

5 - DIAGNOSIS AND TREATMENT

Dermatologists can usually diagnose striae clinically, and no skin biopsy is required. It is important to try to determine the most likely cause of striae in each patient. If a systemic disease is suspected, further work-up may be indicated.

Stretch marks do not require treatment, as they are benign, asymptomatic skin findings, but they can be addressed if they represent a significant cosmetic concern for the patient. Several physical and topical treatment modalities aimed at ameliorating striae appearance are available, including:

• Pulsed dye laser (PDL) therapy
• Non-ablative and ablative fractional laser therapy
• Topical retinoids (e.g.: tretinoin)
• Superficial dermabrasion
• Phototherapy
• Chemical peels
• Intense pulsed light (IPL) therapy
• Radiofrequency
• Microneedling

However, treatment of striae can be challenging and results unpredictable, as the above therapies are not always effective.

Importantly, treatment of stretch marks that develop in pregnant women is usually delayed until after delivery because of potential negative effects of therapies, particularly retinoids, on the foetus.

6 - TIPS FOR MANAGING

Every patient with bothersome striae should see a Dermatologist for adequate diagnosis, counselling and treatment.

People suffering from striae should regularly apply moisturisers on the affected skin. Use of topical retinoids may be beneficial in early striae, but it is contraindicated in pregnant and breastfeeding women. Laser therapies should be cautiously selected and performed.

Several interventions for the prevention of striae are often discussed in the context of pregnancy, but their efficacy has not been established to date.