Thanks for the query. From the clinical history provided it seems that your sister is suffering from an allergy to vegetables like Ladies finger. To prevent this it is advisable that she stops taking that particular food item for the time being. You can also get an allergy test done to rule out other causes of allergy. In case of severe itching anti allergic medications (like levocetirizine, hydroxyzine, fexofenadine) may be used. After obtaining the panel of allergy test you can consult your physician for further advise. Hope this helps.