Fingertip units is a term coined by CC Long and AY Finlay who, in an article published in 1991 , described a convenient way to measure how much cream to prescribe to a patient with skin disease. Accurate prescription is particularly important for topical steroids.
A fingertip unit describes the amount of cream squeezed out of its tube onto the end of the finger as shown.
Dose of cream in a fingertip unit varies with age:
- Adult male: one fingertip unit provides 0.5 g
- Adult female: one fingertip unit provides 0.4 g
- Children of four years approximately 1/3 of adult amount
- Infants six months to one year approximately 1/4 of adult amount
Amount of cream used varies with body part:
- One hand: apply one fingertip unit
- One arm: apply three fingertip units
- One foot: apply two fingertip units
- One leg: apply six fingertip units
- Face and neck: apply 2.5 fingertip units
- Trunk, front & back: 14 fingertip units
- Entire body: about 40 units
An adult female applies a cream once daily to both arms. She uses 2.4g in one day (2 arms x 3 fingertip units x 0.4g = 2.4 g). This is 16.8 g per week (7 x 2.4 g).
A 30 g tube should last her two weeks. But if she applies it twice daily (4.8 g/day), the tube will be finished in less than a week (33.6 g/week).
An adult male applies a cream once daily to both feet and both hands. He uses about 3 g per day (2 feet x 2 units PLUS 2 hands x 1 unit, x 0.5 g = 3.0 g). This works out as 21 g/week (7 x 3 g).
A 50 g tube should last him about 2 1/2 weeks.
A baby has a cream applied twice daily to the entire body, i.e. about 10 g daily.