Pressure sore-like ulcers on acneiform papules caused by EGFR inhibitors.

Dear Editors, Epidermal growth factor receptor (EGFR) inhibitors such as erlotinib and gefitinib have been established as effective therapies for non-small cell lung cancer, pancreatic cancer, colorectal cancer, and head and neck cancer (1). However, a number of skin manifestations, such as acneiform papules, xerosis, photosensitive dermatitis, pruritus, perionychia and vasculitis have been reported in patients receiving EGFR inhibitors (2). Herein, we describe two Japanese patients who developed pressure sore-like ulcers on acneiform papules due to EGFR inhibitor treatment. Such ulcers have not been reported in the literature before. Case 1: A 71-year-old woman suffering from metastatic and recurrent non-small cell lung cancer developed follicular papules or pustules on her face, trunk, buttocks and extremities after receiving gefitinib for 3 months. Furthermore, pressure sore-like ulcers with yellow necrotic tissue appeared on the sacral area (Figure 1A), the ischial area and the trochanter major area (Figure 2B). These ulcers were composed of multiple ulcerated papules or pustules. Clobetasol propionate was applied topically to the lesions and the ulcers, and the administration of gefitinib was then discontinued. The acneiform papules cleared within 10 days, and epithelialization of the ulcers occurred within 3 weeks. Case 2: A 74-year-old man suffering from non-small cell lung cancer developed multiple follicular papules or pustules on the face, hypogastrium, inguen, ischial area and posterior aspect of the thigh after receiving erlotinib for 2 weeks. The pustules under pressure or shear (ischial area and inguen) were ulcerated and resembled a pressure sore. The posterior aspect of the thigh was subjected to pressure when the patient sat on a chair. Betamethasone butyrate propionate was administered topically to the lesions, including the ulcers. Moreover, the patient was advised to use a cushion to reduce the shearing and pressure. The lesions started to improve within few days. Finally, the papules and pustules cleared (Figure 2A), and epithelialization of the ulcers occurred within 3 weeks (Figure 2B). EGFR is overexpressed in many solid cancers and is often associated with cancer development, growth, proliferation, metastasis and angiogenesis (3). It is also expressed in a wide variety of normal tissues, including epidermis, hair follicles and sebaceous glands. As a result, the skin is the organ that is most frequently affected by toxicity due to anti-EGFR therapy. Acneiform follicular papules or pustules without comedones or Propionibacterium acnes develop on the face, anterior upper chest and scalp in more than 90% of patients (2). A B