Small white grains on the male coronal area may be due to pearly penile papules, allergies or warts. 1. pearly penile papules: pearly papules are located in the penile coronal groove, around the glans appear small pimples, mostly pearly white, a small number of reddish color, usually no pain, no breakage, and the patient does not have obvious self-conscious symptoms. The cause of the disease is not yet fully understood, considering the possibility of long foreskin, poor local hygiene, coronal secretions and dirt long-term stimulation. 2. allergy: male coronary groove belongs to the external genital organs, is more sensitive parts, due to the underwear material and other reasons, can lead to local allergies, and then appeared in the coronary long small white grain, may be accompanied by itching feeling. 3. Warts: are caused by human papillomavirus infection, occurring in the external genital area. The disease is contagious and spreads mainly through sexual contact. Initial symptoms are not obvious, and when the condition worsens, skin lesions will appear at the glans coronal groove, and the color may be light red, white and so on. Men with small white grains at the coronal sulcus are advised to seek prompt medical attention before the cause is clarified, and then make use of dermoscopy, acetic acid white test as well as pathohistological examination for diagnostic analysis.