Is it permissible to remove the hijab due to suffering from allergic contact eczema that causes severe and persistent itching when wearing it, given the absence of an effective treatment, and is it permissible to resume wearing it once the itching subsides?

Covering the head of a woman in front of non-mahram (definition) men is obligatory by the consensus of scholars, based on the Almighty’s saying: ﴿And let them cast their head-coverings over their bosoms﴾ and ﴿let them draw their outer garments close around themselves﴾. Allah the Almighty has permitted elderly women who are past childbearing to lay aside their outer garments, provided that they are not displaying adornment, but this is on condition that they still cover their heads. It is permissible to uncover the head out of necessity or pressing need, such as a doctor examining a patient for treatment. However, going out for work and uncovering the head is forbidden and is not considered a necessity if the woman is not in need of the work, or if she can work in her home, or among other women.