Abstract: Methods and devices are provided for sweat inducement, which is useful in diagnostics, such as diagnosis of cystic fibrosis in a patient. The method includes applying a microneedle patch, which comprises microneedles which comprise pilocarpine or another sweat-inducing agent, to the skin of the patient effective to cause the microneedles to penetrate across the epidermis and into the dermis releasing the pilocarpine or another sweat-inducing agent into the skin in an amount effective to induce secretion of sweat from the skin. The secreted sweat can be collected and analyzed, for example by measuring chloride concentration in the sweat, which may be indicative of cystic fibrosis.