What is Diphencyprone (DPCP)?
Diphencyprone (DPCP) is a chemical which causes the body to react by stimulating the body’s immune system. It is used as a cream which is applied to the skin.
When is Diphencyprone used?
DPCP is used when a melanoma has spread to the skin. It works best when the metastases in the skin are small and near the surface of the skin. It helps to prevent the melanoma from spreading and it can cause skin metastases to disappear.
What does using Diphencyprone involve?
You will be reviewed in clinic by the Consultant Dermatologist and if DPCP is the right treatment for you we will:
- Make you allergic to DPCP by applying a small amount at high concentration (2% DPCP in acetone) to your skin as a patch test.
- We apply it to your upper inner arm and cover it. This remains undisturbed for 2 days – you mustn’t wash the area during this time.
- You should get an angry reaction which is red, raised and itchy for approximately 2-5 days after the patch test has been applied. This means you have become allergic to the DPCP.
- We will contact you to evaluate the response by phone or see you in person in the clinic.
If it is a ‘good’ response we will arrange for treatment to commence.
Application of Diphencyprone:
- 10-14 days after we have made you allergic to DPCP, you will start DPCP in aqueous cream. The strength will be much weaker than that applied in the patch test.
- You will be shown how to apply the DPCP cream to your skin by the doctor or nurse in the clinic. Gloves should be worn for this process and disposed of safely. (Gloves & disposal bag will be supplied)
- Wash the DPCP cream off after 10-12 hours using warm soapy water.
- You should develop an eczema like reaction 2-4 days after application.
- Everybody reacts differently to the cream so the strength may need to be increased or reduced depending on how you respond. We are aiming for an eczematous reaction which you can cope with.
- Development of an eczematous reaction is needed for the treatment to work.
- The DPCP cream is applied once weekly to affected area as shown by doctor or nurse.
- Red rash, occasionally mild blistering is to be expected (see image).
- Adverse reaction: extreme red rash, itching, extensive severe blistering and weeping are of concern. If in doubt please contact us (details below).
- If a severe reaction occurs STOP the treatment until you have contacted us. We will then advise on further management.
- Initially follow up may be by telephone or e mail to assess reaction to the patch test and the initial dose of DPCP cream.
- Regular follow up is 1-2 monthly but may be changed if there are any worries or concerns, or at the discretion of the Consultant.
- Your GP will be informed of all treatment plans.
Long term effect
The DPCP cream needs to be continued regularly in order to maintain the body’s immune reaction against the melanoma cells in the skin. This cream may be used indefinitely.
A ‘blue ink’ effect may appear in the skin following regular treatment and looks like a tattoo. This is nothing to be concerned about. It indicates that the body’s immune cells are fighting the melanoma cells. The blue colour is caused by melanin within cells of the immune system.
Consultant Secretary: +44 1603 288210
Specialist Nurse: +44 1603 288365
Repeat prescriptions: 01603 288210 or 01603 288365
Br J Dermatol. 2016 May;174(5):1141-2. doi: 10.1111/bjd.14314. Epub 2016 Feb 11
Download here: bjd.14314