Fingertip Unit
A fingertip unit (FTU) is the amount of cream or ointment squeezed from a standard tube (5 mm nozzle) along an adult index finger, from the tip to the first crease. The term was coined by Long and Finlay in Clinical and Experimental Dermatology (1991). One adult-male FTU is about 0.5 g and an adult-female FTU about 0.4 g; two FTUs are roughly 1 g. One FTU covers skin about twice the area of a flat adult hand with fingers together (DermNet; Patient.info). It is the standard way to dose Topical Corticosteroids such as Hydrocortisone and Clobetasone Butyrate. The NHS hydrocortisone page and the Eumovate leaflet both tell parents to use it.
Fingertip Unit [defines] Topical Corticosteroids Fingertip Unit [relates] Hydrocortisone Fingertip Unit [relates] Clobetasone Butyrate
For children the FTU is still measured on an adult finger. The parent then uses their own hand to estimate how much of the child’s skin is affected. The age-banded children’s table below is published by Patient.info and reproduced in the prescription Eumovate leaflet. (FTUs per application):
| Body area | 3–6 months | 1–2 years | 3–5 years | 6–10 years |
|---|---|---|---|---|
| Face and neck | 1 | 1.5 | 1.5 | 2 |
| Arm and hand | 1 | 1.5 | 2 | 2.5 |
| Leg and foot | 1.5 | 2 | 3 | 4.5 |
| Front of chest and abdomen | 1 | 2 | 3 | 3.5 |
| Back including buttocks | 1.5 | 3 | 3.5 | 5 |
For a toddler aged 1–2, treating the whole body therefore needs about 1.5 + 2×1.5 + 2×2 + 2 + 3 = 13.5 FTU, or roughly 7 g per application. DermNet estimates about 10 g a day for twice-daily whole-body application in a baby.
Fingertip Unit [relates] Atopic Dermatitis
Conflict: [DermNet, reviewed 2023] says a 4-year-old needs about 1/3 of the adult amount (adult face/neck 2.5 FTU, which implies about 0.8 FTU). [Patient.info, 2023] gives 1.5 FTU for face/neck at age 3–5, which is more than half the adult dose. Unresolved — add to open_questions.
The tool exists to fix two opposite errors. With Steroid Phobia, parents spread a smear too thin and under-treat flares. Without a measure, potent creams can be overused on thin-skinned sites, raising the risk of Skin Atrophy and HPA Axis Suppression. The AFP 2009 review and DermNet also use FTUs to work out how big a tube to prescribe. For example, 2 g once daily makes a 30 g tube last about 15 days. Parents can check how fast a tube runs out against the expected quantity.
Fingertip Unit [opposes] Steroid Phobia Fingertip Unit [prevents] Skin Atrophy Fingertip Unit [prevents] HPA Axis Suppression
Connections
- Topical Corticosteroids — dosing measure for TCS in children, source: DermNet; Patient.info
- Hydrocortisone — NHS advises FTU dosing for OTC hydrocortisone, source: NHS
- Clobetasone Butyrate — Eumovate Rx leaflet prints the children’s FTU table, source: emc PIL 3807
- Steroid Phobia — under-dosing that FTUs are meant to correct, source: Patient.info
- Skin Atrophy — overuse risk that measured dosing limits, source: AFP 2009