Changes in the lip vermillion found in own observation in patients with chronic GvHD resemble lichen planus, lichen sclerosus, discoid lupus erythematosus, and actinic cheilitis (summary presented in Table 2). There is scarce literature on dermoscopic characteristics of lip vermillion in selected inflammatory or autoimmune dermatoses, mainly in the form of case reports or case series, that we discuss below.

Lichen planus on the lip has a specific sign—Wickham striae—which is considered to be a marker of active disease [15]. Various patterns of those shiny whitish structures were described, including reticular, linear, and circular [15]. Its pathogenesis is equivocal—it is explained by the increase in granular cell layer in the epidermis by some authors and to the focal increase in the epidermal activity by others [15]. Wickham striae are usually seen on violaceous background, often accompanied by scaling, with dotted and linear peripheral vessels [15]. In our cohort, similar structures were seen in three patients suffering from lichen planus-like chronic GvHD (one of them is shown in Fig. 1a, b).

Clinical (a, c, e, g) and dermoscopic (polarized light, tenfold magnification) (b, d, f, h) presentations of lip vermillion in patients with chronic graft-versus-host disease (cGvHD). a (Patient 4). In the clinical picture focal hyperpigmentation and depigmentation areas and shiny whitish linear scarring-like structures were noted. b (Patient 4). Dermoscopy showed white peripheral scale, multiple diffuse brown dots, white parallel and perpendicular shiny lines. Dotted and linear vessels, blood spots, and Wickham striae are also visible. c (Patient 1). In clinical examination of atrophic lips focal hyperpigmented areas were seen. d (Patient 1). Dermoscopy revealed patchy white scale, parallel brown and white lines, dotted, linear without bends, and linear curved vessels of unspecific distribution, blurred vermillion border. e (Patient 12). Clinical presentation of dried, flaking lips with multiple brown hyperpigmented areas. f (Patient 12). Dermoscopy showed white peripheral scale, white and brown parallel, angulated, and perpendicular lines, brown dots, dotted and linear vessels. g (Patient 6). In the clinical picture dry lip vermillion, hyperpigmentation, and whitish areas were noted. h (Patient 6). Dermoscopy revealed white and yellow peripheral scale, diffuse brown and white parallel lines, brown dots, white globules, dotted vessels of unspecific distribution, and blood spots

The white, linear, dense homogenous area in long-standing lesions of lichen sclerosus in dermoscopy was suggested to correlate with the fibrosis affecting the upper dermis seen in histology [16]. In our patients, linear, white homogenous areas in biopsy-proven lichen sclerosus-like cGvHD were found (Fig. 1c, d). Dermoscopy of some patients demonstrated parallel and perpendicular white lines (Figs. 1e, f, 2g, h).

Clinical (a, c, e, g) and dermoscopic (polarized light, tenfold magnification) (b, d, f, h) presentations of lip vermillion in patients with cGvHD. a (Patient 13). In the clinical picture chapped lips were seen. b (Patient 13). Dermoscopy showed white peripheral scale, white diffuse parallel and perpendicular lines, dotted vessel of unspecific distribution, and multiple linear almost parallel erosions. c (Patient 8). Clinical presentation involved chapped lips and central linear ulceration. d (Patient 8). Dermoscopy showed short, white, diffuse parallel lines between numerous dotted and linear vessels, linear erosions, and ulceration. e (Patient 2). In the clinical picture whitish, cobblestone-like areas covering all surfaces of the upper lip, ulceration, and several linear erosions were observed. f (Patient 2). Dermoscopy revealed focal white globules as a predominant feature, dotted and linear vessels, linear erosions, and ulceration. g (Patient 5). In the clinical picture multiple, hyperpigmented foci were seen. h (Patient 5). Dermoscopy revealed white patchy scale, brown and gray dots, white globules, and white and brown perpendicular and angulated lines with dotted and linear vessels. Linear erosions are also visible

In a study concerning mucosal and labial discoid lupus erythematosus the most common dermoscopic signs, present in over half of the patients, were follicular keratotic plugs and scales [17]. In early lesions they were accompanied by perifollicular white halos and in late lesions by telangiectasia and white structureless areas, with additional features present on the lip—brown pigment spots, blood spots, and erosions. Brown dots, linear erosions, and blood spots were also frequently reported in our study (Fig. 1g, h).

Oncological vigilance is of extreme importance in patients after alloHSCT, and oral GvHD is a known risk factor of lip squamous cell carcinoma (SCC). SCC can be preceded by actinic cheilitis that may present in many forms, including pale, flaking, or scaly lips, areas of erythema, chronic ulcerations and erosions, white plaques, blurring of the lip vermillion border, and vermillion atrophy [18]. In our patients the following features were often found: scaling, white structures, blurred vermillion border, linear erosions, and ulceration (Fig. 2a–d).

Dermoscopy of Fordyce spots, which may arise in healthy individuals, showed yellow lobules surrounded by nonarborizing vessels [19]. In one of our patients suffering from cGvHD, multiple yellow white spots occurred after transplantation, resembling Fordyce spots (Fig. 2e, f). These were accompanied by exophytic mucosal lesions. In this case histopathology revealed sclerotic-type GvHD with GvHD-associated angiomatosis.

Despite the progress in alloHSCT procedures, the prevalence of cGvHD continues to grow [20], and it remains one of the main causes of long-term mortality and morbidity for patients surviving for longer than 2 years after alloHSCT [21]. Oral cGvHD is clinically diagnosed by history, context, and clinical examination [12]. According to NIH criteria, lichen planus-like changes belong to diagnostic clinical signs for cGvHD, while erythematous and ulcerative changes are distinctive signs [13]. Oral lesions frequently accompany involvement of other organs and treatment is based on systemic therapy with local topical treatment including high-potency glucocorticosteroids and calcineurin inhibitors [12]. The differential diagnosis of oral changes in the late phase after alloHSCT includes cGvHD but also infectious and other immunological reactions such as Stevens-Johnson syndrome. Clinical history and exclusion of infection are of foremost importance. Histopathology may be not conclusive, as diffuse T cell infiltration was reported in the labial minor salivary glands and in the buccal mucosa in oral cGvHD, with other features including thickening of the epithelium, interface submucosal lymphocytic infiltrate, epithelial atrophy, and basal cell apoptosis and degeneration [12]. Such diffuse T cell infiltration has also been reported in autoimmune or chronic inflammatory diseases that clinically resemble cGvHD [12].