|Year : 2017 | Volume
| Issue : 1 | Page : 25-26
Red dots caught red handed: Dermoscopy of genital psoriasis
Balachandra Suryakant Ankad, Mahajabeen Madarkar
Department of Dermatology, S. Nijalingappa Medical College, Bagalkot, Karnataka, India
|Date of Web Publication||28-Dec-2016|
Balachandra Suryakant Ankad
Department of Dermatology, S. Nijalingappa Medical College, Navanagar, Bagalkot - 587 102,
Source of Support: None, Conflict of Interest: None
Dermoscopy is an in vivo diagnostic technique that aids in the visualization of epidermis, dermoepidermal junction, and papillary dermis. Histopathology contributes tremendously in confirming the clinical diagnosis of unusual presentations of inflammatory skin disorders. Being noninvasive, dermoscopy assists significantly in differentiation of many inflammatory skin disorders which clinically resemble one another. In this report, authors describe the importance of dermoscopy in the diagnosis of genital psoriasis which was mimicking dermatophytic infection and contact dermatitis.
Keywords: Dermoscopy, diagnosis, psoriasis, red dots
|How to cite this article:|
Ankad BS, Madarkar M. Red dots caught red handed: Dermoscopy of genital psoriasis. Clin Dermatol Rev 2017;1:25-6
| Introduction|| |
Psoriasis is a common inflammatory skin disorder whose characteristic features allow for correct clinical diagnosis on most occasions. However, unusual presentations do exist and may cause difficulties in differentiating from similar-looking inflammatory conditions. In such cases, histopathology plays a significant role in confirming the clinical diagnosis.  Localized psoriasis on the genitalia mimics dermatophytic infection, contact dermatitis, and plasma cell balanitis making skin biopsy necessary for confirmation of diagnosis. 
In this report, authors highlight the importance of dermoscopy in the diagnosis of localized psoriasis affecting the shaft of penis.
| Clinical Problem|| |
A 27-year-old male presented to dermatology outpatient department with an asymptomatic patch on the shaft of the penis [Figure 1] since 45 days. There was no history of trauma preceding the onset of the lesion. There was no history of any topical medication as well. On examination, an erythematous patch measuring 1 cm × 1 cm was observed on the shaft of penis 1.5 cm behind the corona sulcus. Minimal scaling was noted on the surface of lesion. Differential diagnoses of contact dermatitis (probably due to condom), dermatophytic infection, plasma cell balanitis, and psoriasis were considered. Systemic examination and relevant investigations were unremarkable. Patient was explained about the condition and advised for potassium hydroxide preparation on the scrapings collected from the lesion and skin biopsy for confirmatory diagnosis. Due to invasive nature of investigations, patient refused for carrying out these procedures.
|Figure 1: Clinical image showing erythematous patch with minimal scaling|
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| Diagnostic Pearl|| |
Dermoscopy of the lesion was considered as it is a noninvasive technique. Contact dermoscopy under nonpolarized mode using ultrasound gel as interface medium was performed using videodermoscopy (FotoFinder™, Germany) at ×20, ×70, and ×120 magnifications. To visualize epidermal and superficial dermal structures, nonpolarized mode was employed in this case. Probe of videodermoscopy was held gently on the lesion taking care not to obscure vascular structures. Images could be seen directly on the monitor and magnification could be changed anywhere between ×20 and ×120. Static images at the above-mentioned magnifications were saved and analyzed. Clinical diagnosis was blinded to the dermoscopist (one of the authors, MM). At ×20 magnification, red dots arranged regularly and homogeneously on a red background were seen [Figure 2]. At ×70 magnification, ring pattern of red dots was observed [Figure 3], and the red globules were seen to be arranged in a glomerular pattern at ×120 magnification [Figure 4]. White scales were seen at all magnifications. All the patterns of red dots observed in this case were consistent with the characteristic dermoscopic findings of psoriasis. 
|Figure 2: Videodermoscopy showing regular red dots and white scales on erythematous background (Nonpolarized, ×20)|
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|Figure 3: Videodermoscopy showing red dots (yellow arrows) arranged in ring pattern and white scales (black arrow) (Nonpolarized, ×70)|
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|Figure 4: Videodermoscopy showing red globules (yellow arrows) arranged in glomerulus pattern and white scales (black arrow) (Nonpolarized, ×120)|
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Dermoscopy is a noninvasive tool which aids in the visualization of color variegations and vessel structures in the skin lesions. In contact dermatitis, red dots are arranged in clusters with yellowish scales.  Dermoscopic patterns of red dots or globules arranged in a homogeneous, regular, or ring-like fashion have been described as common and characteristic findings in psoriasis. 
| Significance|| |
Dermoscopy is being used in the differentiation of many inflammatory skin disorders. It has become a standard diagnostic aid in clinical practice because it is noninvasive and easy to perform.  In this case, dermoscopy was very useful in confirming the diagnosis of localized psoriasis affecting the shaft of the penis. Thus, dermoscopy is a useful diagnostic technique in a clinical scenario where an invasive diagnostic procedure is refused or not feasible.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]