Striking External Genitals (Differential Diagnosis)

4-year-old toddler with striking external genitals. Below the penis-like structure there is a longitudinal groove with a narrow orifice and vulva. A scrotum and testicles are missing. There is also a pigmentation of the external genitals and a hairy pubic region. These abnormal external genitals belong to an adrenogenital syndrome in a toddler (type II according to Prader). This differential diagnosis is important because some of the newborns with adrenogenital syndrome have an additonal syndrome of salt loss with life-threatening signs of adrenal cortical hypofunction some days after birth, for instance vomiting; also because the virilization of the external genitals may not be as obvious as in the presented case, or because the patient is a boy. In contrast to the hypertrophic pyloric stenosis, there is a hyperpotassemic, hyponatremic metabolic acidosis in adrenogenital syndrome. Extraabdominal or extragastrointestinal causes are an additional differential diagnosis of hypertrophic pyloric stenosis, such as - besides adrenogenital syndrome - frequent urinary tract infections (frequently in $$skro_01??££urinary tract malformations§§) , progressive hydrocephalus, $$hydr_02??££shunt dysfunction,§§ or $$comm_01??££head injury§§ .