Jesus Sanchez-Martin

Dermoscopic Patterns of Purpuric Lesions

D IFFERENT CLINICAL FORMS OF PURPURA are the result of either noninflammatory or inflammatory changes within or around the blood vessel walls. Dermoscopy helps in distinguishing between these forms beyond the standard examination. The basic dermoscopic patterns are (1) homogeneous, (2) mottled, (3) perifollicular (with purpuric halos), and (4) epidermal purpuric. The homogeneous purpuric pattern characterizes a noninflammatory form of purpura, such as bleeding diathesis (Figure 1 shows the lesions on a patient with acenocoumarol overdose), or vessel wall or supporting stroma abnormalities, such as senile or steroid purpura (Figure 2). This pattern consists of wide, homogeneous, structureless purpuric areas. The mottled purpuric pattern suggests a purpuric lesion of the inflammatory type, such as leukocytoclastic vasculitis (LV) (Figure 3) and pigmented purpuric dermatosis (PPD) (Figure 4). This pattern consists of multiple small, speckled, blurred purpuric blotches (Figure 3) and/or more defined purpuric globules (PGs) over a purple and, later, orange-brown background (Figure 4). Some variations of this basic pattern can be recognized according to the intensity of the background, the presence of necrosis, and the presence of other vascular structures. Purpuric globules may appear as an isolated finding (Figure 3) or surrounding a larger purpuric background. The background color may obscure the globules if it is prominent or when large tissue necrosis is present. Necrotic lesions are seen as whitish blue patches (Figure5 shows LV lesions) or as eroded areas with hemorrhagic crusts in the context of the purpuric areas (Figure6 shows LV lesions). Vascular structures are usually obscured in purpuric lesions, but PGs may be surrounded by linear vessels in some cases of urticaria vasculitis (Figure 7), in some forms of PPD, and in insectbite reactions or by glomerularlike vessels in patients with associated venous stasis (Figure 8). The perifollicular dermoscopic pattern of scurvy consists of purpuric halos centered by hair follicles (Figure 9). “Corkscrew hairs” and follicular hyperkeratosis can also be visualized under the dermatoscope. Other purpuric patterns include purpuric or black blood spots of subcorneal and subungual hemorrhage (Figure 10) and hemorrhagic crusts over eroded lesions (Figure 11 shows lesions of eczema). Histopathologically, the homogeneous and the mottled purpuric patterns correspond to extravasated erythrocytes in the dermis, either with capillaries devoid of inflammatory cells (the homogeneous pattern) or with variable inflammatory changes (the mottled pattern). The dermal erythrocyte extravasation that is related to PGs of LV is secondary to fibrinoid degeneration of small blood vessels, with a mixed neutrophilic infiltrate. In contrast, PGs of PPD are related to variable amounts of erythrocytes, lymphocytes, and siderophages surrounding swollen blood vessels within the upper part of the dermis, with or without epidermal changes. Differences in the color of the background partially reflect the condition of the extravasated erythrocytes (intact erythrocytes in purple lesions or siderophages in yellow lesions).

Dermoscopy of Small Basal Cell Carcinoma: Study of 100 Lesions 5 mm or Less in Diameter

It has been assumed that dermoscopy features of smalland large-size basal cell carcinoma (BCC) are similar, although the effect of size on the frequency of dermoscopic structures has not specifically been investigated. Given that the diagnostic performance of dermoscopy in melanoma detection was proven to be lower for small melanocytic lesions (<6 mm in diameter), an effect of small size cannot be excluded in BCC. The aim of this study was to assess whether small BCC ( 5 mm in diameter) have a similar frequency of dermoscopic features as large BCC.

Dermoscopy for the Screening of Common Urticaria and Urticaria Vasculitis

T HE LESIONS ARE FROM THE ARM OF A 35-YEARold man (Figure 1) (scale indicates millimeters), the trunk of a 15-year-old girl (Figure2), the leg of a 51-year-old woman (Figure 3), and the leg of a 20-year-old woman (Figure 4). All patients had erythematous, urticariform lesions. The first 2 patients had common urticaria, and the others had urticarial vasculitis. The handheld dermoscope ( 10 original magnification) serves to clinically discriminate between these diseases noninvasively. Figure 1 and Figure 2 show common urticaria dermoscopically, disclosing prominent, sometimes reticular red lines. These red lines correspond histologically with ectatic, horizontal, subpapillary vessels and are different from vascular red dots (papillary vessels). Lesions of common urticaria may also show structureless avascular areas, devoid of vascular findings, representing areas where the vessels are obscured by prominent edema (Figure 2). Purpuric structures are not seen in common urticaria wheals. Figure 3 and Figure 4 show urticarial vasculitis dermoscopically disclosing purpuric dots or globules in a patchy orange-brown background. These structures are associated with extravasation and degradation of red blood cells. Red lines and purpuric globules are not specific to urticaria and urticarial vasculitis, respectively; however, the recognition of these structures will help as a first-line clinical screening tool for discriminating between common urticaria and urticarial vasculitis in daily practice.

Evaluation of a Program for the Automatic Dermoscopic Diagnosis of Melanoma in a General Dermatology Setting

&NA; The authors have indicated no significant interest with commercial supporters.

Perifollicular white halo: a dermoscopic subpattern of melanocytic and nonmelanocytic skin lesions.

T HE DERMOSCOPIC IMAGES SHOWN IN Figure 1A and B and Figure 2 are from lesions of different skin conditions, but they all have a peculiar dermoscopic finding in common: a perifollicular white halo (PWH). The PWH is a well-demarcated, round, homogeneous whitish area, flat or prominent, measuring 0.5 to 1.5 mm in diameter, that surrounds the opening of the hair follicle (the “full-moon” sign). Figure 1 shows the dermoscopic (A and B) and histopathologic (C and D [stained with S-100 protein]) features of PWHs of melanocytic nevi, revealing a diminution of melanocytes and pigment in the skin adjacent to the hair follicle. The black on the stratum corneum seen in Figure 1C and D is India ink that has been placed on the gross specimens over the PWHs (arrows). Figure 2 shows the dermoscopic pattern of PWHs on the forehead of a child after sun exposure and tanning (A) as well as 2 processes related to dermal sun damage: actinic purpura of Bateman (B) and erythrosis interfollicularis colli of Leder (C and D), which are surrounded by structureless purpuric areas and linear vascular structures, respectively. This dermoscopic sign therefore has a variable significance. Histologically, PWHs of melanocytic nevi correspond to a perifollicular decrease in the number of either junctional or dermal melanocytes, a decrease in the pigment load within keratinocytes, or a decrease in the number of melanophages. The PWHs of erythrosis interfollicularis colli papules are histologically correlated with abnormal and elevated sebaceous glands. The pilosebaceous area is rendered more prominent by the surrounding actinically damaged dermis. The PWHs of senile purpura probably represent a pseudo-hypomelanosis, which is an increased visualization of the follicular contour that is spared and accentuated by the surrounding dermal hemorrhage. Also, perifollicular depigmented halos have been reported in patients with Darier disease and in darkskinned individuals. These cases illustrate a peculiar dermoscopic sign (the PWH) and emphasize the usefulness of dermoscopy for highlighting subtle clinical differences between the interfollicular and the follicular areas of the skin in daily practice.

Letter: benign subcutaneous emphysema after a skin biopsy.

A 76-year-old female patient required evaluation at our dermatologic department because of 2 days of long swelling of her left arm. Fever or general malaise were not present. A skin biopsy had been made over the area 3 days before. On examination, a notable, diffuse, crackling sound (crepitus) was heard upon palpation extending from the wrist to the elbow (Figure 1). Erythema, induration, local heat, or necrosis was not present. A loosely sutured biopsy wound was evident near the elbow. Pressure over this area was applied to assess if purulent discharge was present. Numerous, large, clear bubbles mixed with a serohematic exudate became evident (Figure 2). On making a clinical diagnosis of benign SE secondary to the biopsy injury, the sutures were removed and the subcutaneous air was forced out by local pressure. After this maneuver, the SE resolved within a few days, and no relapse occurred. The absence of air within muscle on both the radiograph and the echography of the arm confirmed that a deep, gasproducing soft tissue infection was not present. Circumferential SE was noted on the upper extremity radiograph but not on the chest radiograph.

Letter: Benign Subcutaneous Emphysema after a Skin Biopsy: LETTER TO THE EDITOR

A 76-year-old female patient required evaluation at our dermatologic department because of 2 days of long swelling of her left arm. Fever or general malaise were not present. A skin biopsy had been made over the area 3 days before. On examination, a notable, diffuse, crackling sound (crepitus) was heard upon palpation extending from the wrist to the elbow (Figure 1). Erythema, induration, local heat, or necrosis was not present. A loosely sutured biopsy wound was evident near the elbow. Pressure over this area was applied to assess if purulent discharge was present. Numerous, large, clear bubbles mixed with a serohematic exudate became evident (Figure 2). On making a clinical diagnosis of benign SE secondary to the biopsy injury, the sutures were removed and the subcutaneous air was forced out by local pressure. After this maneuver, the SE resolved within a few days, and no relapse occurred. The absence of air within muscle on both the radiograph and the echography of the arm confirmed that a deep, gasproducing soft tissue infection was not present. Circumferential SE was noted on the upper extremity radiograph but not on the chest radiograph.