Clinical and Dermoscopic Correlation in Secondary Syphilis: A Report of Three Cases

Dear Editor, Secondary syphilis has a varied presentation and includes macular, papular, pustular, lichenoid, and psoriasiform lesions.1 Therefore, dermoscopy can be utilized as an important adjunct in improving diagnostic accuracy. Case 1 A 19-year-old homosexual male presented with multiple red raised scaly lesions on both palms and feet and on the scrotum for one month. He had unprotected anal intercourse five months before the symptoms. Cutaneous examination showed erythematous scaly plaques on palms, soles, and scrotum Figure 1a and c. Dermoscopic examination of the palmar plaque revealed an erythematous background with scales located in the skin furrow, along with a collarette of scales (Biett’s sign) Figure 1b and Supplementary Figure 1d. Dermoscopy of the scrotal plaque revealed a pinkish hue, dotted vessels, focal white areas, and focal scaling at the periphery Supplementary Figure 1e. The venereal disease research laboratory (VDRL) test was reactive with 1:32 dilution, and the treponema pallidum hemagglutination assay (TPHA) was positive.Figure 1: (a) Clinical image showing multiple erythematous scaly papules on both palms, with a few lesions exhibiting Biett’s collarette (green square). (b) Dermoscopy (Dermlite DL4, 10× magnification) under polarised light showing an erythematous background (red arrow) and scales in furrows (blue arrow). (c) Clinical image of the scrotum showing multiple erythematous scaly papules and plaquesCase 2 A 24-year-old unmarried male presented with multiple red, raised, asymptomatic scaly lesions on the body and patchy hair loss of six weeks. He had a history of genital ulcer and multiple unprotected sexual intercourses with commercial sex workers. General examination revealed generalized lymphadenopathy, including epitrochlear lymphadenopathy. Clinical examination revealed patchy alopecia diffusely on the scalp (moth-eaten alopecia) and multiple erythematous scaly papules on the face, trunk, and extremities Supplementary Figure 2a and b. Buschke-Olendorff sign was positive. Dermoscopic examination under polarized light of the scalp revealed an erythematous and brownish background, empty hair follicles, vellus hairs, black dots, and linear branching vessels, while on the palms, it showed similar findings as case 1 Supplementary Figure 2c and d. Case 3 A 32-year-old pregnant female in the second trimester presented with a one-week history of multiple asymptomatic raised lesions on her face and genitalia. Clinical examination revealed multiple scattered flat papules with a smooth surface on the vulva and a solitary erythematous scaly annular plaque on the left cheek Supplementary Figure 3a and b. Dermoscopic examination revealed an orangish background, dotted vessels, follicular plugging, rosettes, and focal scaling predominant at the periphery Supplementary Figure 3c. VDRL and TPHA were positive. Dermoscopy can assist in the diagnosis of secondary syphilis and differentiate it from other disorders. Although there is no standardized dermoscopic criteria for diagnosing secondary syphilis, several case reports have consistently reported similar results.2 Our patients’ dermoscopic findings, along with the histopathological correlation, are summarized in Table 1. Similar findings have been described before by Errichetti et al.3 and Tognetti et al.4Table 1: Dermoscopic findings along with histopathological correlationDermoscopy can also help differentiate it from other common mimics. The common dermoscopic features of various differential diagnoses include guttate psoriasis, which is characterized by a uniform arrangement of dotted blood vessels on a dull or bright red background, accompanied by diffuse white scaling. Pityriasis rosea demonstrates an unspecific pattern of dotted blood vessels, with overlying brown pigmented or white scales that may be located peripherally or centrally, and without a defined direction of peeling. Pityriasis lichenoides chronica is characterized by a combination of non-dotted and focally distributed dotted vessels, along with orange-yellowish structureless areas and focal superficial scales. Erythema annulare centrifugum is identified by a homogeneous collarette of fine, fragile scales, with an irregular, thinner scaling edge and no clear direction of peeling. Visualization of features like the color of the lesion, scaling, and its progression and vascular patterns helps in excluding other differentials. Although serology is a commonly used test, dermoscopy can serve as a useful adjunct in early diagnosis. However, further studies with large sample sizes and controlled methodologies are required to validate these potential benefits. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patients have given their consent for their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest. Use of artificial intelligence (AI) We have not used artificial intelligence.Supplementary Figure 1: (d) Dermoscopy (Dermlite DL4, 10× magnification) of the palmar plaque under polarised light showing Biett’s collarette (yellow arrow). (e) Dermoscopic examination (Dermlite DL4, 10× magnification) of the scrotal plaque under polarised light showing a pinkish background (black arrow), dotted vessels (blue arrow), focal white areas (yellow arrow), and focal scaling at the periphery (red arrow)Supplementary Figure 2: (a) Clinical image showing multiple discrete to coalescing alopecic patches present diffusely on the scalp (moth-eaten alopecia). (b) Clinical image showing multiple erythematous scaly macules and papules on the left palm, with a few lesions exhibiting Biett’s collarette (blue square). (c) Dermoscopy (Dermlite DL4, 10 × magnification) under polarized light showing an erythematous and brownish background (red arrow), white dots (blue arrow), vellus hairs (black arrow), black dot on the periphery (yellow arrow), and dilated and tortuous vessels (white arrow). (d) Dermoscopy (Dermlite DL4, 10 × magnification) under polarized light showing an erythematous background (black arrow), dotted vessels in furrows (red arrow), and Biett’s collarette (blue arrow)Supplementary Figure 3: (a) Clinical image showing multiple scattered flat white papules with a smooth surface on the vulva (Condylomata lata). (b) Clinical image showing solitary erythematous scaly annular plaque on the right cheek (white arrow). (c) Dermoscopy (Dermlite DL4, 10 × magnification) under polarized light showing an orangish background (black arrow), dotted vessels (green arrow), follicular plugging (yellow arrow), and focal scaling predominant at the periphery (blue arrow)Supplementary Figure 4: (a) Pan-dermal perivascular and periadnexal inflammatory infiltrate along with hemosiderin deposition (brown arrow) (Hematoxylin and eosin 20 ×). (b) Epidermis with nonhomogeneous melanin (yellow arrow). Vertically oriented dilated blood vessels in papillary dermis (green arrow) along with dilated longitudinal vessels in the superficial dermis (blue arrow). Dermis also exhibits angiocentric granulomatous inflammation (black arrow) accompanied with endothelial cell swelling and obscuration of the vasculature (Hematoxylin and eosin 100 ×). (c) Abundant plasma cells (red arrow) toward the periphery of the granuloma (Hematoxylin and eosin 400 ×). (d) Dense lymphohistiocytic infiltrate rich in plasma cells (red arrow) (Hematoxylin and eosin 400 ×)