If you have very sensitive skin or you already know that menthol, camphor or fragranced products can irritate you, it is sensible to patch-test this cream before using it regularly around the thumb. Apply a very small amount to a limited area of intact skin, such as a small patch near the intended application site, and wait to see whether redness, itching, burning or unusual discomfort develops.
The cooling and warming effect from menthol and camphor is part of the sensory feel of the product, but that sensation should not be confused with medical action. For some people it feels soothing after repetitive hand use; for others, especially those with reactive or damaged skin, it may feel too strong. Using less product will not always prevent irritation if you are sensitive to these ingredients, so your skin’s response is the most important guide.
Do not use the cream on cracked, bleeding or freshly damaged skin, as richer formulas with aromatic cooling or warming ingredients can sting in those situations. If the area is already inflamed, unusually painful, swollen or worsening, choose appropriate professional advice instead of trying to cover the issue with a cosmetic product.