However, vesicles and pustules can both be visible, for example: When dyshidrotic dermatitis and palmoplantar psoriasis coexist When vesicles in dyshidrotic dermatitis become superinfected When patients with palmoplantar psoriasis become sensitized (eg, to topical corticosteroids) and develop an allergic contact dermatitis When palmoplantar psoriasis is triggered (koebnerized) by an allergic contact reaction Many disorders other than dermatitis can affect the hands and feet.