This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Autoimmune skin disorders, Subject name: Dental
Carpet tack sign seen in - 
Select and explain. 
A. Syphilis, B. Psoriasis, C. Lupus vulgaris, D. DLE
D: DLE
Answer: D: DLE 
Explanation: Carpet tack sign ( tin tack sign) In DLE, characteristic lesions are well-defined erythematous plaques with paially adherent scales entering a patulous follicle. When the scale is removed, its undersurface shows horny plugs that had occupied follicles. This is called the carpet tack or tintack sign.However, carpet tack sign is not diagnostic of DLE. It is also seen in seborrheic dermatitis and pemphigus foliaceous. But in DLE, on removal of scale, bleeding may be seen due to adherent scales unlike in pemphigus foliaceous/seborrheic dermatitis, where the scales are loose. ijdvl journal residents page. Scaly signs in dermatology