There is no known effective treatment for MDE. Sunscreens, colchicine, and topical retinoic acid have been tried without good success.15,16
(See Chapters 108 and 151)
Striae are very common and usually develop between the ages of 5 and 50 years.
They occur about twice as frequently in women as in men. They commonly develop during puberty, with an overall incidence of 25%–35%,23,24 or during pregnancy, with an incidence of 77%.25
The factors leading to the development of striae have not been fully elucidated. Striae distensae are the results of breaks in the connective tissue, resulting in dermal atrophy. Many factors, including hormones (particularly corticosteroids), mechanical stress, and genetic predisposition, appear to play a role.
During puberty, striae appear in areas where there is a rapid increase in size. In girls, the most common sites are the breasts, thighs, hips, and buttocks, whereas in boys, they are seen on the shoulders, lumbosacral region, and thighs. Other less common sites include the abdomen, upper arms, neck, and axillae.
Striae distensae are a common finding on the abdomen, and less so on the breasts and thighs, of pregnant women, especially during the last trimester. They are more common in younger primigravidas than in older pregnant women and are associated with larger weight gain and with babies of higher birth weight. Striae gravidarum can be associated with a higher risk of lacerations during vaginal delivery.26
Striae are usually multiple, symmetric, well-defined linear atrophic lesions that follow the lines of cleavage. Initially, striae appear as red-to-violaceous elevated lines (striae rubra) (see Fig. 107-3). Over time, the color gradually fades, and the lesions become atrophic, with the skin surface exhibiting a fine, white, wrinkled appearance (striae alba).24 The striae can measure several centimeters in length and a few millimeters to a few centimeters in width. The striae associated with systemic corticosteroid therapy and Cushing syndrome can be larger and more widely distributed.
Histologic findings show a decrease in dermal thickness and in collagen in the upper dermis. The collagen bundles are thinned and lie parallel to the epidermis, but they are also arranged transversely to the direction of the striae. Alterations in elastic fibers are variable, but dermal elastin can be fragmented, and specific elastin staining can demonstrate a marked reduction in visible elastin content compared with adjacent normal dermis.27 There is absence of both hair follicles and other appendages.
The diagnosis of striae distensae is usually simple, but the differential diagnosis does include linear focal elastosis (elastotic striae) that was first described by Burket et al in 1989.28 Linear focal elastosis is characterized by rows of yellow palpable striae-like bands on the lower back. Unlike striae, the lesions are raised and yellow rather than depressed and white. Elderly men are most commonly affected, although cases in teenagers have been described. Linear focal elastosis is probably not an uncommon condition. Histologically, there is a focal increase in the number of elongated or fragmented elastic fibers and a thickened dermis. It is postulated that linear focal elastosis may represent an excessive regenerative process of elastic fibers and could be thought of as a keloidal repair of striae distensae.29
Striae distensae have no medical consequences, but they are frequently distressing to those affected. As stretch marks tend to regress spontaneously to some degree over time, the usefulness of treatments that have been tried without case controls is difficult to assess. Topical treatments that have shown some improvement of early stage striae are: tretinoin 0.1% cream,30 a combination of 0.05% tretinoin/20% glycolic acid, or 10% l-ascorbic acid/20% glycolic acid.31 Several lasers have been used in treating striae: the 585-nm pulsed-dye laser has been demonstrated to be of some efficacy in improving the appearance of striae rubra but has no effect on stria alba32; improvement in the leukoderma of the striae alba was noted with 308-nm excimer laser but maintenance treatment is required to sustain the cosmetic benefit.33 The long-term future of treatment strategies is encouraging with the advance in laser technologies.
Idiopathic Atrophoderma of Pasini and Pierini
Epidemiology and Pathogenesis
Idiopathic atrophoderma of Pasini and Pierini is a form of dermal atrophy that presents as one or several sharply demarcated depressed patches with no outpouching, usually on the back of adolescents or young adults.34 Whether atrophoderma is a nonsclerotic, primarily atrophic variant of morphea or a separate distinct entity is still debated.35–39 Its relationship to morphea is favored by its striking clinical and histologic similarities to the atrophy seen at sites of regressing plaques of morphea. Antibodies to Borrelia burgdorferi have been reported.37 Typical lesions of morphea, lichen sclerosus, and atrophoderma have been observed to occur simultaneously in the same patient but in different areas, supporting the view that these conditions are related. In a series of 139 patients, 17% had white induration in the central portions of their atrophic lesions, and 22% had superficial plaques of morphea coexisting in areas outside of their atrophic foci.35 However, to some, the different course and outcome of atrophoderma of Pierini and Pasini as compared with morphea justifies preservation of a distinct name.
This disorder is more frequently encountered in women than in men, with a ratio of 6:1. It usually starts insidiously in young individuals in the second or third decades of life. A congenital case was recently reported.40 The lesions usually occur on the trunk, especially on the back and lumbosacral region, followed in frequency by the chest, arms, and abdomen.37 The distribution is often symmetric and bilateral.
The lesions are single or multiple and usually round or ovoid, ranging in size from a few centimeters to patches covering large areas of the trunk (Fig. 67-4). They are usually asymptomatic and lack inflammation. When lesions coalesce, they can form large, irregular, brown patches but can be hypopigmented.41 The surface of the skin is normal in appearance, and there is no skin induration or sclerosis.
Atrophoderma of Pasini and Pierini. Brownish depressed lesions on the lower back.
The borders or edges of these lesions are sharply defined, and they are usually described as abrupt, “cliff drop” borders ranging from 1 to 8 mm in depth, although they can have a gradual slant.34 These depressed patches are characteristic and give the impression of inverted plateaus, or, if multiple lesions are present, they can have the appearance of Swiss cheese. They are even more apparent when present on the back because the dermis is thicker in this area. The skin surrounding the patches is normal in appearance, and there is no erythema or lilac ring as in morphea.
The course of this benign disease is progressive, and lesions can continue to appear for decades before reaching a standstill. Transformation to generalized morphea has not been observed.
The histologic picture is generally not diagnostic. The epidermis is usually normal or slightly atrophic. Collagen bundles in the mid- and reticular dermis show varying degrees of homogenization and clumping. Dermal thickness is eventually reduced when compared with adjacent normal skin.38 Some irregular clumping and loss of elastic fibers were described in earlier case reports,34 but in most series, no abnormality was seen with elastic tissue stains35,37; therefore, this is not of diagnostic value. The appendages are usually preserved. If sclerodermatous changes appear in preexisting patches, the histology reveals varying degrees of collagen sclerosis resembling morphea.
The differential diagnosis is to be made with active lesions of morphea that usually present as indurated, often hyperpigmented plaques with a characteristic peripheral lilac rim.
No treatment has been proved effective. Dramatic response to oral hydroxychloroquine was recently reported in one patient.42
Follicular atrophoderma refers to dimple-like depressions at the follicular orifices. It can occur as an isolated defect of limited extent, in association with a variety of disorders in which hair follicles are plugged with keratin, or with rare genodermatoses.43,44
Distinctive ice-pick depressions around hair follicles can be seen most commonly on the back of the hands or feet and on the cheeks. These pitted scars can present at birth or early in life. A family history may be present. Follicular atrophoderma occurs in the conditions described in the following sections.
Atrophoderma vermiculatum is a term that applies when the lesions are found exclusively on the cheeks. It is a condition that can either occur sporadically, be inherited as an autosomal dominant disorder, be part of a group of related diseases including keratosis pilaris atrophicans, or be associated with various syndromes.
Multiple inflammatory symmetric papules on the cheeks, presumably centered around hair follicles, may precede the atrophic lesions. These papules then go on to develop pitted, atrophic, and depressed scars in a reticulated or honeycomb pattern (Fig. 67-5). These lesions can extend to the forehead and preauricular regions. This condition usually has its onset in childhood or, less often, around puberty. Men and women seem to be affected equally.45 It usually has a slow progressive course.
Atrophoderma vermiculatum. Multiple, small, pitted scars on the cheek of a young girl.
Keratosis Pilaris Atrophicans
Keratosis pilaris atrophicans46 can include atrophoderma vermiculatum but also a group of closely related disorders that includes keratosis follicularis spinulosa decalvans and ulerythema ophryogenes. These conditions are characterized by keratotic follicular papules, variable degrees of inflammation, and secondary atrophic scarring. Keratosis follicularis spinulosa decalvans begins in infancy with keratotic follicular papules over the malar area and progresses to involve the eyebrows, scalp, and extremities, with scarring alopecia. This condition is inherited in an X-linked recessive fashion in some patients. Ulerythema ophryogenes (or keratosis pilaris atrophicans faciei) differs from atrophoderma vermiculatum by affecting primarily the lateral portion of the eyebrows (ophryogenes) with erythema, follicular papules, and alopecia (Fig. 67-6).
Ulerythema ophryogenes. Erythematous follicular papules and scarring alopecia of the eyebrow.
The underlying pathologic defect in these disorders appears to be abnormal follicular hyperkeratinization of the upper third of the hair shaft leading to obstruction of the growing hair and production of chronic inflammation. The end result of this process is scarring below that level. Histopathology is usually not very helpful and shows dilated follicles, sometimes associated with plugging, inflammation, and sclerosis of dermal collagen.
The various syndromes that include atrophoderma vermiculatum are the Rombo syndrome (milia, telangiectasias, basal cell carcinomas, hypotrichosis, acral cyanosis, and, rarely, trichoepitheliomas), Nicolau–Balus syndrome (syringomas and milia), Tuzun syndrome (scrotal tongue), and finally the Braun–Falco–Marghescu syndrome (palmoplantar hyperkeratosis and keratosis pilaris).
These disorders are mainly a cosmetic but vexing problem. Various topical treatments, including emollients, corticosteroids, tretinoin, and keratolytics, have shown no consistent benefit. Systemic isotretinoin has been shown to stop progression and to induce remission in some cases.46 Dermabrasion as well as carbon dioxide and 585-nm pulsed-dye lasers are other options to improve the appearance of the atrophic scars.47
Bazex–Dupré–Christol Syndrome (OMIM #301845)
Bazex–Dupré–Christol syndrome is characterized by follicular atrophoderma, milia, multiple basal cell carcinomas, hypotrichosis, and localized hypohidrosis.48–50 The follicular atrophoderma described as multiple ice-pick marks or patulous follicles can be found most commonly on the dorsa of the hands. It is inherited in an X-linked dominant fashion, and the gene has been linked to Xq24–q27.48 Subsequently reported findings include facial hyperpigmentation, hair shaft dystrophy, and multiple genital trichoepitheliomas.
Conradi–HüNermann–Happle Syndrome (X-Linked Dominant Chondrodysplasia Punctata, CDPX2, OMIM #302960)
Conradi–Hünermann syndrome is an X-linked dominant disorder that occurs only in girls because it is usually lethal in hemizygous males. The underlying molecular defect consists of mutations in the emopamil-binding protein gene at Xp11.23-p11.22.50 The clinical manifestations include an ichthyosiform scaling erythroderma patterned along the lines of Blaschko that usually resolves during the first year of life and is replaced by bands of follicular atrophoderma.43 Hyperpigmentation, cataracts, scarring alopecia, saddle-nose deformity, asymmetric limb reduction defects, and stippled calcifications of the epiphyses can be seen. Ichthyosis with keratotic follicular plugs containing dystrophic calcification in newborns are distinctive histopathologic features.51