Introduction
Orf is a zoonotic disease formed by epitheliotropic DNA parapoxvirus that contaminates humans from infected goat and sheep [1]; whereas milker’s nodule is an infection developed by paravaccinia virus and shown up in people who have contact with infected cattle’s udder, body and oral cavity [2]. Erythematous, ulcerous, crusted, whitish and/or enclosed with erythematous ring papules and nodules may appear in each of two infections [2]. Also, those can be seen at locations like hands and fingers. Both parapoxviruses are similar as regards clinical and histopathological features. They are different only as to epidemiological ways [2].
Aim
In this study, findings that can help in diagnosis have been investigated by evaluating orf and milker’s nodule dermoscopic features.
Material and methods
Thirty-two patients with 46 lesions whose ages show differences between 3 and 60, diagnosed as orf and milker’s nodule and admitted to the Dermatology Department were included in this study. Biopsy has been taken from all lesions. Diagnosis of these diseases has been made based on clinical, histopathological features and having contact with the animal genus.
This study consists of three stages; determination of orf and milker’s nodule lesion locations and dermoscopic analyses, photography and evaluation of findings.
Structures, determined at dermoscopic examination were classified as vascular and non-vascular ones.
All lesions in the study have been evaluated one by one, their features have been examined either macroscopically or dermoscopically by digital dermoscope (Fotofinder dermoscope II imaging system, TeachScreen Software GmbH, Bad Birnbach, Germany; original magnification: 20×) and data were recorded. Three dermoscopic images of each lesion were recorded, on average. 60% alcohol (ethanol) was used to flatten the skin, to increase the image quality by ensuring light to reach deeper decreasing.
Statistical analysis
All patient data were uploaded to SPSS 17.0 for Windows statistic application software. Data were analyzed by Pearson’s test. It has been accepted as significant if p-value was below 0.05.
Results
Thirty-two patients who have 46 lesions were included in the study. 46.8% (15) of patients were men, 53.2% (17) of patients were women. Average age of the patients was 32.4 ±13.9 and it ranged from 3 to 60 years. The number of lesions was 1–4, disease duration was 7–30 days in studied patients.
56.5% (26) of lesions were orf, and 43.5% (20) of lesions were milker’s nodule. Non-vascular structures observed at orf lesions at dermoscopy were sorted as follows: erosion-ulceration (69.2%, 18), yellow-white ring (57.7%, 15), crust (46.2%, 12), grayish-whitish streaks (26.9%, 7), central yellow-white area (26.9%, 7), blue-gray area (23.1%, 6), orange-yellow streaks (19.2%, 5), and yellow-white globule (11.5%, 3). Vascular structures were sorted as: erythema (100%, 26), black dot (65.4%, 17), erythematous ring (61.5%, 16), dot vessels (61.5%, 16), comma vessels (19.2%, 5), polymorphic vessels (19.2%, 5), glomerular vessels (3.8%, 1), hairpin vessels (0%, 0), and milky-red globule (0%, 0).
Non-vascular structures observed in milker’s nodule at dermoscopy were sorted as follows: erosion-ulceration (55%, 11), grayish-whitish streaks (55%, 11), crust (40%, 8), central yellow-white area (35%, 7), blue-gray area (35%, 7), yellow-white ring (35%, 7), orange-yellow streaks (19.2%, 5), and yellow-white globule (%15, 3). Vascular structures were sorted as erythema (100%, 20), erythematous ring (75%, 15), dot vessels (60%, 12), black dot (55%, 11), hairpin vessels (15%, 3), comma vessels (15%, 3), milky-red globule (10%, 2), polymorphic vessels (15%, 3), and glomerular vessels (5%, 1).
Vascular and non-vascular structures of all lesions are shown in Table 1.
Erythema multiforme was observed in 30.6% of patients who have milker’s nodule while it was not observed in orf patients. Orange-yellow streaks and grayish-whitish streaks were usually observed together. This was statistically significant (p < 0.001).
Discussion
The designation “orf” is derived from the Anglo-Saxon name for cattle and is actually a misnomer for the disease which, though naturally occurring in sheep, goats, and camels [3], has never been reported in cattle. However, milker’s nodule, an endemic pox virus disease in cows, presents with a clinical and histologic picture identical to that of orf [4] and has a similar viral ultrastructural appearance [5]. But there are some opinions that they include different histopathological features [6].
In our study, clinical and dermoscopic features of orf and milker’s nodule were examined. Some similar clinical, epidemiological and dermoscopic findings were observed. Significant findings have not been observed at dermoscopic findings in both diseases.
Lesions were separated into 4 classes generally. They are a yellow-white area in the middle and erythematous ring around in type 1 (Figure 1), usually orange-yellow streaks in the center with violaceous erythematous base and grayish-whitish streaks around and the erythematous ring outside in type 2 (Figure 2), ulceration in the center, yellow-white ring around and erythema ring outside in type 3 (Figure 3), erythema in the center or ulcer-crusted area, yellow-white ring around in type 4 (Figure 4).
The central yellow-white area, one of the observed dermoscopic structures, has been seen in 26.9% of orf lesions and 35% of milker’s nodule lesions. Squamous cell carcinoma and keratoacanthoma are the primary skin diseases among the diseases that show similar dermoscopic features in the center. These types of structures in these diseases are named as central mass of keratin and evaluated as a keratinization sign [7, 8]. An irregular, whitish-yellow amorphous structure in the center has been determined in a case of atypical pyogenic granuloma [9]. Dermoscopic structures, evaluated as orange-yellow streaks have been observed in equal proportions (19.2%) in both diseases. These structures are usually located in the center of lesions and have unspecific borders. One of other dermoscopic structures, grayish-whitish streaks, has been determined as continuation of orange-yellow streaks. Dermoscopic structures like grayish-whitish streaks were determined at pilomatrixoma in the literature [10, 11]. In a study by Zaballos et al., white streaks have been determined in 70% of 10 pilomatrixoma cases [10]. Similar structures have been observed in juvenile xanthogranuloma and lichen planus [11, 12]. White streaks structures have been encountered in pictures of a study about Merkel cell carcinoma although it has not been indicated [13]. Rates of blue-gray areas at orf and milker’s lesions have not been determined as significant (p = 0.373). Dermoscopic formations similar to those structures are named as blue-gray globule at basal cell carcinoma and trichoepithelioma [14, 15]. The blue-gray area has been observed at a 20% rate in a study in which 10 pilomatrixoma cases have been evaluated [10]. Although they have similar shapes, in our opinion, blue-gray areas observed in orf and milker’s nodule depend on the hemorrhagic area which was formed in dermis. In our study, small, dot or splinter shaped hemorrhagic areas that may be observed macroscopically are named as black dot. These formations have been observed in high frequency in both diseases. Vascular formations which have been detected in dermoscopy become important in diagnosis of skin lesions recently. Six main morphological structures are identified among a variety of different vascular structures, namely comma-like, dotted, linear – irregular, hairpin-like, glomerular and arborizing vessels. In addition, there are three specific global structures, namely crown vessels which are located around a whitish core, strawberry vessels and milky red globules [16–19].
Dot vessels correspond to the tips of short and vertically arranged capillaries in lesions of smaller diameters and appear in dermoscopy as very small red dots with a diameter of 0.01 to 0.02 mm. Such vessels may appear in many small and vertical diameter keratinized tumors such as verruca vulgaris, actinic keratosis, seborrheic keratosis, Bowen’s disease (BD), squamous cell carcinoma (SCC) [20]. In our study, dot vessels has been detected in 61.5% of orf lesions, 60% of milker’s nodules.
Comma-like vessels are slightly bended hardly arborizing vessels with a diameter of 1 mm or larger. Comma-like vessels are a variant of dotted and hairpin-like vessels which are some of the basic curved vascular structures [20]. Comma-like vessels is a differential dermoscopic feature in dermal nevus [21]. There are studies which report that 1–45% of all superficial and nodular types of basal cell carcinomas display comma-like vessels [22, 23]. Polymorphic vessels is a combination of two or more vascular patterns of different types. The most frequent combination is the one composed by linear-irregular vessels and dotted vessels. This combination is quite specific to amelanotic/hypomelanotic melanoma of small and medium thickness, particularly when it is located at the core [24]. Furthermore, combinations of linear-irregular vessels and dotted vessels, particularly microarborizing vessels, were detected in Merkel cell carcinoma [13]. Dot vessels and comma-like vessels are the most frequent vascular combinations we have detected.
Erythema multiforme is one of the complications of orf and milker’s nodule. It was much more reported at orf infections than milker’s nodule. Erythema multiforme is thought to be a cell-mediated (delayed type) hypersensitivity reaction that can occur after exposure to certain infections and less commonly to drugs [1]. In our study, six erythema multiforme diseases have been observed in patients who only have milker’s nodule.
Conclusions
As a result, orange-yellow streaks, grayish-whitish streaks, central yellow-white area, black dot, blue-gray area, crust, erosion-ulceration, erythematous ring, yellow-white ring, erythema, dot vessels are the most determined dermoscopic structures in orf and milker’s nodule. Although these formations have been observed in different rates in both diseases, no statistically significant difference has been determined between them. Our opinion is dermoscopy can be a helpful tool for diagnosis even it cannot provide diagnosis of these diseases fully.
Conflicts of interest
The authors declare no conflict of interest.
References
1. Joseph RH, Haddad FA, Matthews AL, et al. Erythema multiforme after orf virus infection: a report of two cases and literature review. Epidemiol Infect 2014; 8: 1-6.
2. Barraviera SRCS. Diseases caused by poxvirus – orf and milker’s nodules – a revıew. J Venom Anim Toxins Incl Trop Dis 2005; 11: 102-8.
3. Dashtseren T, Solovyev BA, Varejka F, et al. Camel contagious ecthyma (pustular dermatitis). Acta Virol 1984; 28: 122-7.
4. Leavell U, Phillips I. Milker’s nodules. Arch Dermatol 1975; 111: 1307-11.
5. Johannensen JV, Krogh HK, Solberg I, et al. Human orf. J Cutan Pathol 1975; 2: 265-83.
6. Groves RW, Wilson-Jones E, MacDonald DM. Human orf and milkers’ nodule: a clinicopathologic study. J Am Acad Dermatol 1991; 25: 706-11.
7. Lin MJ, Pan Y, Jalilian C, et al. Dermoscopic characteristics of nodular squamous cell carcinoma and keratoacanthoma. Dermatol Pract Concept 2014; 4: 9-15.
8. Zalaudek I, Giacomel J, Schmid K, et al. Dermatoscopy of facial actinic keratosis, intraepidermal carcinoma, and invasive squamous cell carcinoma: a progression model. J Am Acad Dermatol 2012; 66: 589-97.
9. Lacarrubba F, Caltabiano R, Micali G. Dermoscopic and histological correlation of an atypical case of pyogenic granuloma. Pediatr Dermatol 2013; 30: 499-501.
10. Zaballos P, Llambrich A, Puig S, et al. Dermoscopic findings of pilomatricomas. Dermatology 2008; 217: 225-30.
11. Song M, Kim SH, Jung DS, et al. Structural correlations between dermoscopic and histopathological features of juvenile xanthogranuloma. J Eur Acad Dermatol Venereol 2011; 25: 259-63.
12. Tan C, Min ZS, Xue Y, et al. Spectrum of dermoscopic patterns in lichen planus: a case series from China. J Cutan Med Surg 2014; 18: 28-32.
13. Harting MS, Ludgate MW, Fullen DR, et al. Dermatoscopic vascular patterns in cutaneous Merkel cell carcinoma. J Am Acad Dermatol 2012; 66: 923-7.
14. Lazaridou E, Fotiadou C, Patsatsi A, et al. Solitary trichoepithelioma in an 8-year-old child: clinical, dermoscopic and histopathologic findings. Dermatol Pract Concept 2014; 4: 55-8.
15. Puig S, Cecilia N, Malvehy J. Dermoscopic criteria and basal cell carcinoma. G Ital Dermatol Venereol 2012; 147: 135-40.
16. Kreusch J, Koch F. Incident light microscopic characterization of vascular patterns in skin. Hautarzt 1996; 47: 264-72.
17. Argenziano G, Zalaudek I, Corona R, et al. Vascular structures in skin tumors. A dermoscopy study. Arch Dermatol 2004; 140: 1485-9.
18. Zalaudek I, Argenziano G, Oliviero M, Rabinovitz H. Dermoscopy of nonpigmented skin tumors. In: Year Book of Dermatology and Dermatologic Surgery 2007. Thiers BH, Lang PG Jr (eds). Elsevier Mosby, Philadelphia 2007; 23-38.
19. Zalaudek I, Argenziano G, Di Stefani A, et al. Dermoscopy in general dermatology. Dermatology 2006; 212: 7-18.
20. Kreusch J. Vascular patterns in skin tumors. Clin Dermatol 2002; 20: 248-54.
21. Menzies SW, Westerhoff K, Rabinovitz H, et al. Surface microscopy of pigmented basal cell carcinoma. Arch Dermatol 2000; 136: 1012-6.
22. Micantonio T, Gulia A, Altobelli E, et al. Vascular patterns in basal cell carcinoma. J Eur Acad Dermatol Venereol 2011; 25: 358-61.
23. Trigoni A, Lazaridou E, Apalla Z, et al. Dermoscopic features in the diagnosis of different types of basal cell carcinoma: a prospective analysis. Hippokratia 2012; 16: 29-34.
24. Menzies SW, Kreusch J, Byth K, et al. Dermoscopic evaluation of amelanotic and hypomelanotic melanoma. Arch Dermatol 2008; 144: 1120-7.
