Do you also (as my doctor) see ok to get a cortisone shot and dimetinden therapy when breastfeeding (1 month old baby) due to a heavy nettle rash?

Probably: Some of the medications you take will get into the breast milk but given the severity of your rash, i think the risk /benefit ratio favors taking the medications since the medications would be present in only trace quantities and not likely to affect your infant. How did you get a nettle rash in an austrian winter? I'd have thought that an edelweiss rash would be more likely :)).