Up to 60% of patients with metastatic colorectal cancer can be treated with one of monoclonal antibodies targeted against epidermal growth factor receptor (EGFR). This treatment is associated with a specific spectrum of toxicity: acne-like rash from limited up to erythema, often with severe pruritus, sometimes combined with other types of skin toxicities (hair and nail changes). Previously in STEPP study investigators shown that pre-emptive treatment with oral doxycycline (200 mg daily), topical steroids and sun blockers reduces the number of more severe skin side effects of panitumumab.