Hello and welcome to HCM.
Thanks for your query.
According to your description you could have the following:
-an allergic reaction
to some thing you come in contact with (accessory) during your shower
(itch mite) requiring a visit to a dermatologist
(but does not dissappear)
which is a symptom of some other underlying infection (requires examination of the type of rash by a doctor)
Either way please visit a doctor at the earliest for proper examination, diagnosis and treatment of your condition.
Feel free to write back to us for any further clarifications.