Continuing Education Activity

Striae, or stretch marks, are indented streaks that often affect the abdomen, buttocks, thighs, back, breasts, axillae and groin. They are divided into striae atrophicans (thinned skin), striae gravidarum (following pregnancy), striae distensae (stretched skin), striae rubrae (red), striae albae (white), striae nigra (black), and striae caerulea (dark blue). These common complaints are difficult to treat. This activity outlines the role of the interprofessional team in the evaluation and management of stretch marks.

Objectives:

• Review the causes of stretch marks.
• Describe the pathophysiology of stretch marks.
• Summarize the treatment options for stretech marks
• Explain the value of improving care coordination among the members of the interprofessional team to educate patients with stretch marks.

Introduction

Striae, or stretch marks, are a common complaint and can be distressing. They may affect the abdomen, buttocks, thighs, breasts, back, axillae and groin. They are classified according to appearance or epidemiology, as:

• striae atrophicans (thinned skin)
• striae gravidarum (following pregnancy)
• striae distensae (stretched skin)
• striae rubrae (red), striae albae (white)
• striae nigra (black)
• striae caerulea (dark blue). 

Striae are difficult to treat effectively. [1][2]

Etiology

Striae are a form of dermal scarring associated with stretching of the dermis. They often result from a rapid change in weight (gain and loss) or are associated with endogenous or exogenous corticosteroids. Proposed mechanisms relate to hormones, physical stretch, and structural alterations of dermal collagen and elastic tissue. Adrenocorticotropic hormones promote fibroblast activity and increase protein catabolism. Pregnancy-related hormones may also contribute. Serum relaxin has been described to be lower in women with striae distensae.[3] Deficiency of fibrillin has also been proposed. [4] Genetic factors are unexplored, except that decreased expression of collagen and fibronectin genes is reported to be associated with striae.

Epidemiology

Striae distensae occur in pregnancy (43% to 88%), puberty (6% to 86%) and obesity (43%). Striae atrophicans follow medical conditions, particularly Cushing syndrome/disease, and treatments, usually exogenous topical or systemic corticosteroids [5], or surgery. Other associated diseases are Marfan syndrome[6], anorexia nervosa[7], various febrile illnesses, and chronic liver disease. Medications associated with striae also include chemotherapy, prolonged antibiotic therapy, contraceptives[8], and neuroleptics.

Striae are more common in females than in males and may be more common in certain races. They can appear more prominent in dark-skinned individuals. A positive family history is a risk factor for striae. During pregnancy, striae are more common in younger women than in older women. Several studies have noted greater prevalence with large abdominal circumference and large weight gain (due to fetal size or polyhydramnios). [9] One study reported that striae were more prevalent in smokers than non-smokers.

Pathophysiology

Pathophysiology is thought to involve elastases released from mast cells and macrophage activity. [10] Elastolysis of the mid-dermis is followed by a reorganization of collagen and fibrillin.

Histopathology of striae rubrae reveals excessive fine elastic fibers in the papillary dermis with thicker tortuous fibers in the periphery, with perivascular lymphocytes, dilated dermal vessels and edema. There are reduction and reorganization of elastin and fibrillin fibers, and structural changes in collagen fibers, which are thicker and densely packed in parallel rows. Histopathology of striae albae shows epidermal atrophy, loss of rete ridges, less vascularity, and densely packed, thin and scar-like horizontal collagen bundles.[4] They appear similar to mature atrophic scars.

Electron microscopy studies have also reported mast cell degranulation, macrophage activation, and elastolysis of mid dermis.[11]

History and Physical

History may explain the appearance of striae by association with stretched skin, for example, in pregnancy, pubertal growth spurt, muscular exercise, or weight gain. Inquire about topical application of potent corticosteroid or prolonged systemic steroids during the recent or remote past. If striae are widespread and none of these explanations are relevant, take a full medical history and conduct a thorough clinical examination.[12]

The initial striae rubrae are slightly raised pink or violaceous linear marks (striae rubrae), which fade over months to years to hypopigmented, atrophic, wrinkled scars (striae albae). The marks are perpendicular to the direction of skin tension. They fade with time. In pregnancy, they occur on the abdomen, breasts, and thighs. In adolescents, they are common on thighs, buttocks, breasts (females) and back (males).

Striae rubrae are sometimes pruritic. Otherwise, striae are asymptomatic. Treatment is sought because of their unsightly appearance.

Evaluation

Authors have used various methods of assessing the type and severity of striae when discussing the efficacy of treatments. These are not standardized or validated. Dermoscopy shows increased melanization in striae rubrae and reduced melanization in striae albae. [13] A biopsy is not necessary or useful.

Treatment / Management

The aim of treatment is to reduce redness, swelling and irritation in striae rubrae, and to increase collagen and elastic fiber production, improve hydration, and reduce inflammation in striae albae.[14]

Topical management is commonly recommended to prevent and treat striae, with very little if any evidence of efficacy, according to several published comprehensive reviews. Clinical trials have been of low quality involving small numbers of subjects.

• Many emollients and over-the-counter cosmeceuticals are marketed and used by pregnant women with the intention of preventing striae distensae or reducing their severity, resulting in considerable effort and expense, despite the considerable uncertainty whether any have benefit. [15]
• Silicone gels are recommended for atrophic scars and may be used in striae distensae. Published results are difficult to interpret.[16]
• Tretinoin cream has been reported to be possibly useful in striae rubrae when compared to placebo over a six-month period. It may result in irritation, redness, and peeling. It should not be applied during pregnancy due to its pregnancy category.[17][18]
• Chemical peels using various acids have been used to treat striae. Efficacy is unknown. 

Physical treatments are also advocated but also have little evidence to support their use.

• Massage is a component of topical therapy, and it is also used in scar management. [19]
• Exposure to broadband ultraviolet radiation can cause repigmentation in striae alba but is reported to have temporary effect with loss of pigmentation within a few months.
• Light and laser therapies have shown improvements in the appearance of striae, although it is uncertain which is best, and at what stage (rubrae, albae) they should be used. [19] Several laser types (e.g., pulse dye laser) target vascular chromophores in striae rubra and are reported to reduce redness and swelling.[20] Fractional lasers (e.g., Erbium-YAG) stimulate fibroblasts to produce collagen and elastin and can cause repigmentation in striae alba.[21]
• Light and lasers cause short-term erythema and oedema. They should be avoided in darker skin types due to greater risk of adverse effects, particularly transient postinflammatory hyperpigmentation and persistent hypopigmentation. Non-ablative devices are safer than ablative lasers.
• Radiofrequency energy devices emit high-frequency alternating electric current producing dermal heat. They are used to tighten the dermis, reduce wrinkles, and improve cellulite. Treatment promotes neocollagenesis, neoelastogenesis, and increased ground substances (proteoglycans) and should theoretically improve the appearance of striae. At least one published study has reported treatment was well tolerated, and the patients were satisfied with the results. A more recent advance has been the delivery of radiofrequency energy to a depth of 3.5 mm using a multiple needle delivery mode. Anecdotal reports are encouraging but proper studies are awaited. [22]
• Other devices used have included microdermabrasion[23], galvanopuncture [24], needling [25], pulsed magnetic fields [22], and ultrasound devices.[26]

The effect of treatments is difficult to assess. For example, laser protocols use differing devices, fluence, pulse duration, spot size and treatment frequency and number.  The utility of combination strategies is unknown.[14]

Platelet-rich plasma injections are also under investigation.[27]

When using any of these modalities, it is important to have standardized pre-treatment and post-treatment photographs. Furthermore, it is important to take these photographs six and twelve months out after the course of treatments. Many published reports do not have standardized photographs, nor do they have long-term follow up. 

Differential Diagnosis

• Anetoderma

• Cutis Laxa

• Linear Focal Elastosis

• Mid-Dermal Elastosis

• Pseudoxanthoma Elasticum

• Striae from Topical Steroidal Abuse

Enhancing Healthcare Team Outcomes

Over time, many striae improve. The best time to perform a treatment (with proper photographs as discussed) is once the striae have stabilized. Many creams for striae are promoted on the internet with little evidence of the efficacy. The public should be made aware that the efficacy is very limited Newer lasers and radiofrequency treatments hold promise as they do try to modify the vascularity and the collagen and perhaps the elastin. Again, there is no clear leader among the many lasers that are promoted. The needle radiofrequency seems to show promise as, in theory, the deeper deliver of the energy may allow "shrinkage" of the striae in all directions, thereby improving the overall appearance. (Level V).