They are both a fungal disease and IMO would be treated the same. Spray with Bioform or Garrett Juice and Potassium Bicarb or cornmeal that has been steeped in the water....or any other organic fungicide.
Here's a good link..by the way, this is what my tomato plants have. Keep treating it every 7 dyas. It thrives on moisture which we've had our share of lately.
http://www.oznet.ksu.edu/dp_hfrr/extens ... rlblht.htm
Both fungi overwinter in plant debris, on seed, or on weeds such as nightshade and horsenettle. Spores of these fungi may be splashed or blown to tomato leaves. Disease development is favored by relatively warm temperatures, abundant rainfall and high relative humidity.
Recommendations: Sanitation measures in the fall will reduce the amount of inoculum available for infection the following year. In the fall, tomato plots should be deep-plowed to bury tomato debris, or dead plants should be removed from the garden and destroyed. Avoid planting tomatoes in the same area of the garden year after year. Clean seed and healthy transplants in the spring also will help control the disease. Both diseases can be controlled effectively with fungicides.