STRIAE DISTENSAE (STRETCH MARKS)

 

WHAT ARE STRIAE DISTENSAE?

Striae distensae is the fancy name for stretch marks. Stretch marks (striae distensae) are an unsightly cosmetic problem that plague many women and some men. Among other reasons for appearing, they are a sign of deterioration and present evidence that the body is aging. They can appear either as small, disconcerting defects or as grotesque, layered deformities in the skin. Patients who are severely affected by stretch marks tend to avoid exposure of the affected area as well as avoid wearing articles of clothing that will reveal these areas, such as swimsuits. For this reason, many patients resort to desperate measures to alleviate them: Wrapping the striae, applying expensive creams and even submitting to surgical procedures all to no avail.

 

WHAT CAUSES STRIAE DISTENSAE?

There is a great deal of controversy as to the exact etiology of striae distensae. In the past they have been attributed to simply stretching and thinning of the connective tissue. Although still poorly understood , today it is believed that they are a form of dermal scarring, in which the dermal collagen ruptures and separates; the intervening gap is then filled with newly synthesized collagen, which then becomes aligned in response to local stress forces. There is absence of hair follicles. There are many clinical situations in which striae arise, and this variability has contributed to the confusion of their etiology. Striae are common in women following pregnancy and at puberty when the breasts and hips enlarge, but they also appear spontaneously in teenage boys across the back and in weight lifters, following a significant weight change or with the use of topical steroids. The maturation of striae is similar to the description of scar resolution. When they first appear, striae are flat and pinkish in color. As they mature, they widen, elongate and become bright purple. After many years, striae turn white and become depressed into the skin. Arem and Kischer reported their analysis of striae in 1980 and concluded that striae are a "form of dermal scarring, in which the dermal collagen ruptures perhaps under the influence of steroids, in some cases and separates; the intervening gap is filled with newly synthesized collagen, which then becomes aligned in response to local stress forces." There since has been further information from both light and electron microscopic studies that indicate striae are a form of miniscars in the dermis.

 

WHO GETS STRIAE DISTENSAE?

Striae distensae appears to be present in most healthy women, originating either during puberty or at the time of the first pregnancy , they also occur in weight lifters, teenage boys across the lower back, as well as in chronic debilitated states, and from excessive use of topical steroids.

 

HOW ARE THEY FORMED?

 Regardless of the associated factors, at the beginning all early striae are flat and have a faint pink coloration. As they mature they widen, elongate , and take on a bright violaceous color. Over several years they fade, turn white, and become depressed. This is characteristic of the formation of a scar in the skin as well.

 

HOW ARE STRIAE DISTENSAE TREATED?

To begin treating stretch marks, first it is necessary to delineate their exact nature. Although their description has caused significant debate, striae were noted hundreds of years ago in the medical literature and histologically delineated in 1889. In the past, many authors have attributed them to the stretching and thinning of connective tissue, but more recent studies have confirmed that they are a form of dermal scarring. In the past ,stretch marks were treated by plastic surgery of the affected areas. Today a more conservative method is being investigated for the treatment of striae distensae called RETIN-A.

 

 

 

 

WHAT ARE RETINOIDS?

Retin-A is a retinoid and is the trade mark for Tretinoin ( retinoic acid, vitamin A acid). It is a derivative of vitamin A. Chemically, Tretinoin is all-trans- retinoic acid. It has been used in the treatment of acne for almost twenty years. Its use has increased since 1988, for the treatment of striae distensae and photoaging skin. Similar retinoids include Renova, Tazorac (more powerful) and Differin creams. Retinoids all work in a similar way. For simplicity we will focus our discussion on Retin A, though the rules apply to all.

 

 

Retin-A Guidelines:

 

1. Treat the lesions as early as possible. Newer stretch marks respond much better than older ones.

2. Retin-A microgel 0.1% or Retin-A, Renova, Tazorac, or Differin should be applied daily onto moist skin.

3. Avoid exposure to direct sunlight to the treated area. Also, do not apply other agents

 to the area being treated, moisturizers and cosmetic products.

4. If irritation results, continue treatments unless the side effects become very painful or infection is suspected the extent to which inflammation plays in the treatment of these lesions is not known.

5. If no benefit is obvious at 12 weeks, discontinue the treatment.

6. If there is significant benefit before 12 weeks, discontinue the treatment and let the inflammation subside. If further benefit is desired and thought to be possible, restart the med and repeat the protocol.

7. It is prudent that Retin-A, Renova, Tazorac, and Differin not be used during pregnancy; therefore, the necessary screening protocols and precautions should be followed.

 

HOW DO RETINOIDS WORK?

Although the exact mode of action of Tretinoin is unknown , there are many effects of this chemical upon the skin when applied topically. It effects both the dermal and the epidermal layer of the skin. Oikarinen et al. demonstrated in 1985, that cultured dermal fibroblasts contain a retinoic acid binding protein. In addition , animal studies have shown an increase in dermal collagen deposition following the application of retinoic acid. Tretinoin can increase the presence of fibroblasts in the area of application. Additionally Tretinoin stimulates mitotic activity and increases turnover of follicular epithelial cells.

 

WHAT ARE THE SIDE EFFECTS OF RETINOIDS?

 

Burning, erythema, irritation and painful vesicular dermatitis was reported among patients.

 

Therapy with Retin A makes the skin more susceptible to sunburn and other adverse effects of the sun.

 

Skin treated with Retin-A may be more vulnerable to excessive exposure to wind or cold.

 

The skin of certain individuals may become excessively red, swollen, blistered, or crusted.

 

There have been reports that areas treated with Retin- A had temporary increase or decrease in the amount of skin pigmentation. The pigment in these areas return to normal either after the skin was allowed to adjust to Retin-A or after the therapy was discontinued.

And finally, as true with any other medications, hypersensitivity to this medication may occur.

 

ARE THERE ANY SIDE AFFECTS ASSOCIATED WITH THE USE OF RETIN-A DURING PREGNANCY?

 

No studies have been conducted in human to establish the safety of Retin-A in pregnant women. But Oral Tretinoin has been shown to be teratogenic in rats when given in doses 1000 times the topical human dose. Topical Tretinoin has not been shown to be teratogenic in rats and rabbits when given in doses 100 and 320 times the topical human dose. But because of the lack of evidence and studied in human the use of this medication is not advised during pregnancy, or period of breast feeding. . It is prudent that Retin-A, Renova, Tazorac, and Differin not be used during pregnancy; therefore, the necessary screening protocols and precautions should be followed.

 

ARE RETINOIDS FDA APPROVED FOR THE TREATMENT OF STRIAE?

No they are not. The FDA has not approved retinoids for the treatment of striae. Though many dermatologists prescribe retinoids for their striae patients, and though there are studies that show some efficacy, this is considered an off label use.