Your rash appears in the winter months - Jan, Feb and March and not in the hot humid summer months. Fungal infection is unlikely as it is expected to be encountered in summer rather than in the winter months. Since your rash always occurs in a particular season, then it is logical to expect that the causative agent is seasonal. This may be an ingestant or an inhalant (e.g. pollen encountered in these months). The improvement taking place may be due to the medication or it may be because the process anyway is a self-limiting one. One should work on these lines. However, proper clinical assessment is essential when the disease is active.