Fennel Seed Ground, Foeniculum vulgare - have problems with your skin, such as minor irritations and burns, a fennel solution can bring soothing relief. Fennel can even be used in an infusion to treat problems like conjunctivitis, an inflammation of the lining of the eye. Add fennel seed to bath teas, milk baths, soap and body powders. In a facial steam or facial mud, fennel will allow the pores to open.