Patients will receive local prophylactic treatment (Diprosone cream) during 8 weeks from the beginning of the EGF-R inhibitors treatment, on the areas of the body susceptible to be affected by folliculitis.

Inclusion Criteria:

• Indication of Cetuximab in patients with metastatic colorectal cancer in association or not with irinotecan, after failure of a chemotherapy treatment with Irinotecan OR
• Indication of Erlotinib, in patients with metastatic Non-Small-Cell Lung Carcinoma, after failure of at least one chemotherapy treatment
• No pre-existing cutaneous toxicity

Exclusion Criteria:

• Contraindication to local corticotherapy
• Previous history of severe hypersensibility reactions (Grade III or IV) due to Cetuximab, Irinotecan or Erlotinib
• Betamethasone or one of excipient product allergy