A practical approach to the assessment of the external genitalia in boys

Male infants and children are frequently referred with parental or health care provider concerns about small penis size. A micropenis is defined as stretched penile length less than 2.5 standard deviations of the mean for age. The term ‘inconspicuous penis’ has been used to describe a group of conditions that result in the penis appearing abnormally small. These conditions include: congenital megaprepuce, trapped penis (secondary to scarring following surgery, most commonly post circumcision), concealed penis (due to enlarged suprapubic fat pad) and webbed penis. Hypospadias is another cause for abnormal penis appearance which can be confused with an inconspicuous penis. Concerns about penile size and appearance can cause significant anxiety for families and older children. It is therefore important for all healthcare providers working with children to have an understanding of the varying pathologies as well as what is considered normal. This short article is aimed at paediatricians and healthcare professionals who might be the first point of contact for families with concerns about penis size. It offers advice about assessment and provides guidance about when onward referral is required.