Answer: Based on your description this could certainly be a case of raincheck. Raincheck is a physiological condition, it is not a disease. It seems to happen when the tomatoes swell quickly due to excessive rain. It is disfiguring and can reduce the shelf life of the tomatoes. It only occurs in response to extremely rainy spells, so new fruit formed since that wet period should not be affected. You could pick off the affected tomatoes if you like. You do not need to pull up your plants -- the rest of your crop should be fine.
In general it is a good idea to to rotate your tomato plantings to prevent possible build up of pest or diseases problems that carry from season to season. It also allows you to rebuild the soil in between tomato planting years by growing other less demanding crops there. If possible allow three years or more between planting tomatoes in the same spot.
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