CED
Experimental dermatology • Concise report
Clinical and Experimental Dermatology
Differentiation of pityriasis lichenoides chronica from guttate psoriasis by dermoscopy E. Errichetti,1 F. Lacarrubba,2 G. Micali,2 A. Piccirillo3 and G. Stinco1 1 Department of Experimental and Clinical Medicine, Institute of Dermatology, University of Udine, Italy; 2Dermatology Clinic, University of Catania, Italy; and 3SOC Dermatologia e Malattie Sessualmente Trasmesse, San Carlo Hospital, Potenza, Italy
doi:10.1111/ced.12580
Summary
Clinical differentiation between pityriasis lichenoides chronica (PLC) and guttate psoriasis (GP) may sometimes be a difficult task, which often requires histological analysis to reach a definitive diagnosis. In this study, PLC and GP lesions were examined using dermoscopy, and the significance of specific dermoscopic findings was investigated in order to facilitate their differentiation and decrease the number of cases requiring biopsy. We found that the incidence of orange–yellowish structureless areas, focal dotted vessels and nondotted vessels was statistically significant in PLC, while the incidence of diffuse dotted vessels was statistically significant in GP.
The clinical differentiation of pityriasis lichenoides chronica (PLC) and guttate psoriasis (GP) may sometimes be a diagnostic challenge; in such cases, histopathological examination helps to differentiate the two conditions. Recently, the application of dermoscopy has also been extended to inflammatory skin disorders in order to assist the clinical diagnosis and decrease the number of cases requiring biopsy.1,2 In this study, PLC and GP lesions were examined using dermoscopy, and the significance of specific dermoscopic findings was investigated.
Report The study was approved by institutional review board of Udine University, and all patients provided written informed consent. This was a cross-sectional study that enrolled eight patients (five men, three women; mean age, 39.1 15.1 years) with biopsy-proven PLC and nine patients (six men, three women; mean age, Correspondence: Dr Giuseppe Stinco, Institute of Dermatology, University of Udine, Ospedale ‘San Michele’ di Gemona, Piazza Rodolone 1, 33013, Gemona del Friuli, Udine, Italy E-mail: [email protected] Conflict of interest: the authors declare that they have no conflicts of interest. Accepted for publication 12 August 2014
ª 2015 British Association of Dermatologists
33.4 14.5 years) with biopsy-proven GP. One dermoscopic image taken of a target lesion from each patient using a manual dermoscope (Heine Delta 20 9 10; Heine Optotechchnik, Herrsching, Germany) equipped with a camera (Coolpix 4500 Nikon Corporation, Melville, NY, USA) was retrospectively reviewed by an independent dermoscopist not aware of the histological diagnosis. Statistical analysis was performed using Stata software (v12; StataCorp 2011, College Station, TX, USA), and the Fisher exact test (results were considered statistically significant at P < 0.010). Seven patients (87.5%) with PLC had trunk involvement, four (50.0%) had involvement of the lower extremities and three (37.5%) had involvement of the lower extremities, while the figures for patients with GP were nine (100.0%), five (55.6%) and three (33.3%), respectively. The specific dermoscopic findings of PLC and GP are summarized in Table 1. We found that the most common dermatoscopic features of PLC (present in seven of the eight cases; 87.5%) were orange–yellowish structureless areas and nondotted vessels (including milkyred areas/globules, linear irregular and branching vessels). Focally distributed dotted vessels were observed in five patients (62.5%), while hypopigmented areas were evident in only one case (Fig. 1a). Dermoscopy of GP lesions revealed in all patients a monomorphic picture quite similar to that commonly found in plaque
Clinical and Experimental Dermatology
1
Dermoscopy of pityriasis lichenoides chronica vs guttate psoriasis E. Errichetti et al.
psoriasis,3–5 with dotted vessels distributed in a diffuse pattern (Fig. 1b). In one case, an additional orange– yellowish structureless area was observed. Statistical analysis showed that the incidence of orange-yellowish structureless areas (P < 0.01), focal dotted vessels (P < 0.01) and nondotted vessels (P < 0.001) was significant in PLC, while the incidence of diffuse dotted vessels (P < 0.001) was significant in GP. Considering the specific pattern of nondotted vessels, we found that only linear irregular vessels (P < 0.01) were significantly associated with PLC, while the incidence of branching vessels (P = 0.03), milky-red areas/globules (P = 0.21), and the presence of hypopigmented areas (P = 0.47), were not significantly different between the groups. To our knowledge, this is the first study concerning the specific dermoscopic features of both GP and PLC. Recently, a dermoscopy study on two patients with pityriasis lichenoides et varioliformis acuta (PLEVA) showed in both cases the presence of papules with a Table 1 Dermoscopic features observed in pityriasis lichenoides chronica and guttate psoriasis.
Dermoscopic finding
Pityriasis lichenoides chronica (n = 8), n (%)
Guttate psoriasis (n = 9), n (%)
Orange–yellowish structureless areas* Hypopigmented areas Dotted vessels Focal distribution* Diffuse distribution* Nondotted vessels* Linear irregular vessels* Linear branching vessels Milky-red areas/globules
7 1 5 5 0 7 6 4 2
1 0 9 0 9 0 0 0 0
(87.5) (12.5) (62.5) (62.5) (0.0) (87.5) (75.0) (50.0) (25.0)
(11.1) (0.0) (100.0) (0.0) (100.0) (0.0) (0.0) (0.0) (0.0)
*P < 0.01 between pityriasis lichenoides chronica and guttate psoriasis.
(a)
central whitish patch, or crusted lesions with an amorphous brownish structure, both surrounded by a well-defined ring of pinpoint and/or linear vascular structures with a targetoid aspect.6 Although both PLEVA and PLC belong to the same spectrum of disease, their dermoscopic differences are easily explained by the different underlying histological findings, which in the acute form are usually more severe, and include necrosis, ulceration, more congestion and dermal microhaemorrhages.7 Manual dermoscopy is a low-cost and noninvasive technique, which may assist in the clinical diagnosis of both PLC and GP. It may also be useful for the differential diagnosis from other dermatoses that clinically may resemble PLC or PG, namely lichen planus, which is characterized by whitish crossing lines (Wickham striae), and pityriasis rosea, which often presents with a yellowish background, dotted vessels and peripheral scales.1 The dermoscopic differences between PLC and GP found in our study are probably related to the known underlying histological features, with the orange–yellowish structureless areas of PLC reflecting extravasated erythrocytes (and consequent haemosiderin degradation products), and the diffusely distributed red dots observed in GP corresponding to tortuous and dilated blood vessels within elongated dermal papillae.7 The different vascular component of PLC, characterized under dermoscopy by nondotted and focal dotted vessels, could be due to dilatation of superficial dermal vessels without a significant and constant papillomatosis.7 This study was uncontrolled and performed on a limited number of patients, and the results do not take into account variability in age, sex and location. Future studies are therefore needed to confirm our preliminary observations.
(b)
Figure 1 (a,b) Dermoscopy of a pityriasis lichenoides chronica papule shows orange–yellowish structureless areas in the centre of the
lesion and some focally distributed dotted vessels (white circle) and various nondotted vessels, including linear irregular (black circle) and branching vessels (white arrowhead), at the periphery. (a) Hypopigmented areas (lighter areas of the surrounding healthy skin) are also evident (black arrow); (b) monomorphic dermoscopic picture characterized by dotted vessels distributed in a diffuse pattern in a lesion of guttate psoriasis.
2
Clinical and Experimental Dermatology
ª 2015 British Association of Dermatologists
Dermoscopy of pityriasis lichenoides chronica vs guttate psoriasis E. Errichetti et al.
References Learning points ● Differential diagnosis between PLC and GP may
sometimes be a difficult task, which often requires histological analysis to reach a definitive diagnosis. ● Dermoscopy has been used recently to assist the clinical diagnosis of inflammatory skin disorders, thus decreasing the number of cases requiring biopsy. ● The most common dermatoscopic features of PLC found in this study were orange-yellowish structureless areas and nondotted vessels (present in seven of the eight cases); focally distributed dotted vessels observed in five patients; and hypopigmented areas (one case only). ● Dermoscopy of GP lesions in all nine patients enrolled in this study revealed a monomorphic picture, with dotted vessels distributed in a diffuse pattern, and in one case, an additional orangeyellowish structureless area was observed. ● We found that the incidence of orange-yellowish structureless areas, focal dotted vessels and non-dotted vessels was statistically significant in PLC, whereas the incidence of diffuse dotted vessels was statistically significant in GP.
ª 2015 British Association of Dermatologists
1 Lallas A, Kyrgidis A, Tzellos TG et al. Accuracy of dermoscopic criteria for the diagnosis of psoriasis, dermatitis, lichen planus and pityriasis rosea. Br J Dermatol 2012; 166: 1198–205. 2 Micali G, Lacarrubba F, Musumeci ML et al. Cutaneous vascular patterns in psoriasis. Int J Dermatol 2010; 49: 249–56. 3 Lallas A, Apalla Z, Tzellos T, Lefaki I. Photoletter to the editor: dermoscopy in clinically atypical psoriasis. J Dermatol Case Rep 2012; 6: 61–2. 4 Stinco G, Buligan C, Errichetti E et al. Clinical and capillaroscopic modifications of the psoriatic plaque during therapy: observations with oral acitretin. Dermatol Res Pract 2013; 2013: 781942. 5 Lacarrubba F, Micali G. Dermoscopy of pityriasis lichenoides et varioliformis acuta. Arch Dermatol 2010; 146: 1322. 6 Musumeci ML, Lacarrubba F, Verzı AE, Micali G. Evaluation of the vascular pattern in psoriatic plaques in children using videodermatoscopy: an open comparative study. Pediatr Dermatol 2014; 31: 570–4. 7 Patterson JW. Psoriasiform and lichenoid dermatitis. In: Practical Skin Pathology: A Diagnostic Approach, 1st edn (Patterson JW, ed). Philadelphia: Elsevier Saunders, 2013; 21–39.
Clinical and Experimental Dermatology
3
Experimental dermatology • Concise report
Clinical and Experimental Dermatology
Differentiation of pityriasis lichenoides chronica from guttate psoriasis by dermoscopy E. Errichetti,1 F. Lacarrubba,2 G. Micali,2 A. Piccirillo3 and G. Stinco1 1 Department of Experimental and Clinical Medicine, Institute of Dermatology, University of Udine, Italy; 2Dermatology Clinic, University of Catania, Italy; and 3SOC Dermatologia e Malattie Sessualmente Trasmesse, San Carlo Hospital, Potenza, Italy
doi:10.1111/ced.12580
Summary
Clinical differentiation between pityriasis lichenoides chronica (PLC) and guttate psoriasis (GP) may sometimes be a difficult task, which often requires histological analysis to reach a definitive diagnosis. In this study, PLC and GP lesions were examined using dermoscopy, and the significance of specific dermoscopic findings was investigated in order to facilitate their differentiation and decrease the number of cases requiring biopsy. We found that the incidence of orange–yellowish structureless areas, focal dotted vessels and nondotted vessels was statistically significant in PLC, while the incidence of diffuse dotted vessels was statistically significant in GP.
The clinical differentiation of pityriasis lichenoides chronica (PLC) and guttate psoriasis (GP) may sometimes be a diagnostic challenge; in such cases, histopathological examination helps to differentiate the two conditions. Recently, the application of dermoscopy has also been extended to inflammatory skin disorders in order to assist the clinical diagnosis and decrease the number of cases requiring biopsy.1,2 In this study, PLC and GP lesions were examined using dermoscopy, and the significance of specific dermoscopic findings was investigated.
Report The study was approved by institutional review board of Udine University, and all patients provided written informed consent. This was a cross-sectional study that enrolled eight patients (five men, three women; mean age, 39.1 15.1 years) with biopsy-proven PLC and nine patients (six men, three women; mean age, Correspondence: Dr Giuseppe Stinco, Institute of Dermatology, University of Udine, Ospedale ‘San Michele’ di Gemona, Piazza Rodolone 1, 33013, Gemona del Friuli, Udine, Italy E-mail: [email protected] Conflict of interest: the authors declare that they have no conflicts of interest. Accepted for publication 12 August 2014
ª 2015 British Association of Dermatologists
33.4 14.5 years) with biopsy-proven GP. One dermoscopic image taken of a target lesion from each patient using a manual dermoscope (Heine Delta 20 9 10; Heine Optotechchnik, Herrsching, Germany) equipped with a camera (Coolpix 4500 Nikon Corporation, Melville, NY, USA) was retrospectively reviewed by an independent dermoscopist not aware of the histological diagnosis. Statistical analysis was performed using Stata software (v12; StataCorp 2011, College Station, TX, USA), and the Fisher exact test (results were considered statistically significant at P < 0.010). Seven patients (87.5%) with PLC had trunk involvement, four (50.0%) had involvement of the lower extremities and three (37.5%) had involvement of the lower extremities, while the figures for patients with GP were nine (100.0%), five (55.6%) and three (33.3%), respectively. The specific dermoscopic findings of PLC and GP are summarized in Table 1. We found that the most common dermatoscopic features of PLC (present in seven of the eight cases; 87.5%) were orange–yellowish structureless areas and nondotted vessels (including milkyred areas/globules, linear irregular and branching vessels). Focally distributed dotted vessels were observed in five patients (62.5%), while hypopigmented areas were evident in only one case (Fig. 1a). Dermoscopy of GP lesions revealed in all patients a monomorphic picture quite similar to that commonly found in plaque
Clinical and Experimental Dermatology
1
Dermoscopy of pityriasis lichenoides chronica vs guttate psoriasis E. Errichetti et al.
psoriasis,3–5 with dotted vessels distributed in a diffuse pattern (Fig. 1b). In one case, an additional orange– yellowish structureless area was observed. Statistical analysis showed that the incidence of orange-yellowish structureless areas (P < 0.01), focal dotted vessels (P < 0.01) and nondotted vessels (P < 0.001) was significant in PLC, while the incidence of diffuse dotted vessels (P < 0.001) was significant in GP. Considering the specific pattern of nondotted vessels, we found that only linear irregular vessels (P < 0.01) were significantly associated with PLC, while the incidence of branching vessels (P = 0.03), milky-red areas/globules (P = 0.21), and the presence of hypopigmented areas (P = 0.47), were not significantly different between the groups. To our knowledge, this is the first study concerning the specific dermoscopic features of both GP and PLC. Recently, a dermoscopy study on two patients with pityriasis lichenoides et varioliformis acuta (PLEVA) showed in both cases the presence of papules with a Table 1 Dermoscopic features observed in pityriasis lichenoides chronica and guttate psoriasis.
Dermoscopic finding
Pityriasis lichenoides chronica (n = 8), n (%)
Guttate psoriasis (n = 9), n (%)
Orange–yellowish structureless areas* Hypopigmented areas Dotted vessels Focal distribution* Diffuse distribution* Nondotted vessels* Linear irregular vessels* Linear branching vessels Milky-red areas/globules
7 1 5 5 0 7 6 4 2
1 0 9 0 9 0 0 0 0
(87.5) (12.5) (62.5) (62.5) (0.0) (87.5) (75.0) (50.0) (25.0)
(11.1) (0.0) (100.0) (0.0) (100.0) (0.0) (0.0) (0.0) (0.0)
*P < 0.01 between pityriasis lichenoides chronica and guttate psoriasis.
(a)
central whitish patch, or crusted lesions with an amorphous brownish structure, both surrounded by a well-defined ring of pinpoint and/or linear vascular structures with a targetoid aspect.6 Although both PLEVA and PLC belong to the same spectrum of disease, their dermoscopic differences are easily explained by the different underlying histological findings, which in the acute form are usually more severe, and include necrosis, ulceration, more congestion and dermal microhaemorrhages.7 Manual dermoscopy is a low-cost and noninvasive technique, which may assist in the clinical diagnosis of both PLC and GP. It may also be useful for the differential diagnosis from other dermatoses that clinically may resemble PLC or PG, namely lichen planus, which is characterized by whitish crossing lines (Wickham striae), and pityriasis rosea, which often presents with a yellowish background, dotted vessels and peripheral scales.1 The dermoscopic differences between PLC and GP found in our study are probably related to the known underlying histological features, with the orange–yellowish structureless areas of PLC reflecting extravasated erythrocytes (and consequent haemosiderin degradation products), and the diffusely distributed red dots observed in GP corresponding to tortuous and dilated blood vessels within elongated dermal papillae.7 The different vascular component of PLC, characterized under dermoscopy by nondotted and focal dotted vessels, could be due to dilatation of superficial dermal vessels without a significant and constant papillomatosis.7 This study was uncontrolled and performed on a limited number of patients, and the results do not take into account variability in age, sex and location. Future studies are therefore needed to confirm our preliminary observations.
(b)
Figure 1 (a,b) Dermoscopy of a pityriasis lichenoides chronica papule shows orange–yellowish structureless areas in the centre of the
lesion and some focally distributed dotted vessels (white circle) and various nondotted vessels, including linear irregular (black circle) and branching vessels (white arrowhead), at the periphery. (a) Hypopigmented areas (lighter areas of the surrounding healthy skin) are also evident (black arrow); (b) monomorphic dermoscopic picture characterized by dotted vessels distributed in a diffuse pattern in a lesion of guttate psoriasis.
2
Clinical and Experimental Dermatology
ª 2015 British Association of Dermatologists
Dermoscopy of pityriasis lichenoides chronica vs guttate psoriasis E. Errichetti et al.
References Learning points ● Differential diagnosis between PLC and GP may
sometimes be a difficult task, which often requires histological analysis to reach a definitive diagnosis. ● Dermoscopy has been used recently to assist the clinical diagnosis of inflammatory skin disorders, thus decreasing the number of cases requiring biopsy. ● The most common dermatoscopic features of PLC found in this study were orange-yellowish structureless areas and nondotted vessels (present in seven of the eight cases); focally distributed dotted vessels observed in five patients; and hypopigmented areas (one case only). ● Dermoscopy of GP lesions in all nine patients enrolled in this study revealed a monomorphic picture, with dotted vessels distributed in a diffuse pattern, and in one case, an additional orangeyellowish structureless area was observed. ● We found that the incidence of orange-yellowish structureless areas, focal dotted vessels and non-dotted vessels was statistically significant in PLC, whereas the incidence of diffuse dotted vessels was statistically significant in GP.
ª 2015 British Association of Dermatologists
1 Lallas A, Kyrgidis A, Tzellos TG et al. Accuracy of dermoscopic criteria for the diagnosis of psoriasis, dermatitis, lichen planus and pityriasis rosea. Br J Dermatol 2012; 166: 1198–205. 2 Micali G, Lacarrubba F, Musumeci ML et al. Cutaneous vascular patterns in psoriasis. Int J Dermatol 2010; 49: 249–56. 3 Lallas A, Apalla Z, Tzellos T, Lefaki I. Photoletter to the editor: dermoscopy in clinically atypical psoriasis. J Dermatol Case Rep 2012; 6: 61–2. 4 Stinco G, Buligan C, Errichetti E et al. Clinical and capillaroscopic modifications of the psoriatic plaque during therapy: observations with oral acitretin. Dermatol Res Pract 2013; 2013: 781942. 5 Lacarrubba F, Micali G. Dermoscopy of pityriasis lichenoides et varioliformis acuta. Arch Dermatol 2010; 146: 1322. 6 Musumeci ML, Lacarrubba F, Verzı AE, Micali G. Evaluation of the vascular pattern in psoriatic plaques in children using videodermatoscopy: an open comparative study. Pediatr Dermatol 2014; 31: 570–4. 7 Patterson JW. Psoriasiform and lichenoid dermatitis. In: Practical Skin Pathology: A Diagnostic Approach, 1st edn (Patterson JW, ed). Philadelphia: Elsevier Saunders, 2013; 21–39.
Clinical and Experimental Dermatology
3
