**3. Conclusions**

Psoriasis is a common skin disease with different clinical presentations. Generally, clinical evaluation is enough for diagnosis, though dermoscope is a helpful and noninvasive examination technique that enhances true diagnosis ratio. Knowing psoriasis' and its differentials' dermoscopic features may reduce requirement for histopathological examination and also makes rapid diagnosis possible in life-threatening conditions such as erythroderma. Note that regularly distributed dotted vessels on a reddish background are the most important clues for any variant of psoriasis. In doubtful cases, histopathological examination should be done for verifying the diagnosis as a gold standard technique.
