Brief Answer: Kindly see the details below Detailed Answer: Hi, Welcome and thanks for posting your query to healthcare magic. After reading your query I can make out that you want to know the exact time period when the tests for detection of herpes can be performed in a lady who had vesicular eruptions 3 weeks ago. According to the above situation the lady can undergo the simple tests for herpes antibodies- IgM and IgG for HSV 1 & 2 at the earliest possible. TO explain you simply- In herpes there is incubation period (period form exposure to the clinical appearance of herpes vesicles) is 2-7 days. It may be delyed for weeks also. It is a sole fact that the herpes antibodies must come positive within days after the clinical appearance of herpes lesions/ vesicles. There are certain cases where the incubation period or we say the appearance of lesion may get delayed to few weeks. In these cases the IgM antibody or the test result may not show positive status accordingly. Ig M tells the recent infection and Ig G tells late infection. HSV 1 is for oral lesions and HSV 2 is for genital lesions. So if we consider the above stated case to be herpes vesicles then the test must have come positive as per the above dictum. Either or both of IgM or IgG can be positive according to the time status of the problem. I also suggest that the male partner should also go for the tests for herpes antibodies- IgM and IgG for HSV 1 & 2. I hope this clears all your doubts. Tell me if you have any further quires. with regards, Dr. Sanjay Kumar Kanodia (MD - Skin & Sexually Transmitted Diseases)

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