He wrote that he had only encountered it four times in his career and gave brief descriptions of each case, listing three common traits:

The individual is tainted [by heredity] (hereditär belastete)
The subjects primary attraction is to children, rather than adults. The acts committed by the subject are typically not intercourse, but rather involve inappropriate touching or manipulating the child into performing an act on the subject.He mentions several cases of pedophilia among adult women (provided by another physician), and also considered the abuse of boys by homosexual men to be extremely rare. Further clarifying this point, he indicated that cases of adult men who have some medical or neurological disorder and abuse a male child are not true pedophilia and that, in his observation, victims of such men tended to be older and pubescent. He also lists pseudopaedophilia as a related condition wherein "individuals who have lost libido for the adult through masturbation and subsequently turn to children for the gratification of their sexual appetite" and claimed this is much more common.Austrian neurologist Sigmund Freud briefly wrote about the topic in his 1905 book Three Essays on the Theory of Sexuality in a section titled The Sexually immature and Animals as Sexual objects. He wrote that exclusive pedophilia was rare and only occasionally were prepubescent children exclusive objects.
On the other hand, a person who acts upon these urges yet experiences no distress about their fantasies or urges can also qualify for the diagnosis. Acting on sexual urges is not limited to overt sex acts for purposes of this diagnosis, and can sometimes include indecent exposure, voyeuristic or frotteuristic behaviors, or masturbating to child pornography. Often, these behaviors need to be considered in-context with an element of clinical judgment before a diagnosis is made. Likewise, when the patient is in late adolescence, the age difference is not specified in hard numbers and instead requires careful consideration of the situation.Ego-dystonic sexual orientation (66 .1 F 66 .1) includes people who acknowledge that they have a sexual preference for prepubertal children, but wish to change it due to the associated psychological or behavioral problems (or both). Debate regarding criteria
There was discussion on the DSM-IV-TR being overinclusive and underinclusive. Its criterion A concerns sexual fantasies or sexual urges regarding prepubescent children, and its criterion B concerns acting on those urges or the urges causing marked distress or interpersonal difficulty. Several researchers discussed whether or not a "contented pedophile"—an individual who fantasizes about having sex with a child and masturbates to these fantasies, but does not commit child sexual abuse, and who does not feel subjectively distressed afterward—met the DSM-IV-TR criteria for pedophilia since this person did not meet criterion B. Criticism also concerned someone who met criterion B, but did not meet criterion A.