Where the burden of parasites in the body is light, there may be no symptoms.Certain worms may cause particular constellations of symptoms. For instance, taeniasis can lead to seizures due to neurocysticercosis. Mass and volume
In extreme cases of intestinal infestation, the mass and volume of the worms may cause the outer layers of the intestinal wall, such as the muscular layer, to tear. This may lead to peritonitis, volvulus, and gangrene of the intestine. Immunological response
As pathogens in the body, helminths induce an immune response. Immune-mediated inflammatory changes occur in the skin, lung, liver, intestine, central nervous system, and eyes. Signs of the bodys immune response may include eosinophilia, edema, and arthritis. An example of the immune response is the hypersensitivity reaction that may lead to anaphylaxis. Another example is the migration of Ascaris larvae through the bronchi of the lungs causing asthma. Secondary effects
Immune changes
In humans, T helper cells and eosinophils respond to helminth infestation. It is well established that T helper 2 cells are the central players of protective immunity to helminths, while the roles for B cells and antibodies are context-dependent. Inflammation leads to encapsulation of egg deposits throughout the body. Helminths excrete into the intestine toxic substances after they feed. These substances then enter the circulatory and lymphatic systems of the host body.Chronic immune responses to helminthiasis may lead to increased susceptibility to other infections such as tuberculosis, HIV, and malaria.
This has been suggested to be due to in situ conversion of adrenal androgens into estrone and then estradiol (via local 17β-HSD) in breast tissue (where aromatase activity may be particularly high).The symptoms of AEXS, in males, include heterosexual precocity (precocious puberty with phenotypically-inappropriate secondary sexual characteristics; i.e., a fully or mostly feminized appearance), severe prepubertal or peripubertal gynecomastia (development of breasts in males before or around puberty), high-pitched voice, sparse facial hair, hypogonadism (dysfunctional gonads), oligozoospermia (low sperm count), small testes, micropenis (an unusually small penis), advanced bone maturation, an earlier peak height velocity (an accelerated rate of growth in regards to height), and short final stature due to early epiphyseal closure. The incidence of gynecomastia appears to be 100%, with 20 of 30 male cases opting for mastectomy according to a review.In females, symptoms of AEXS include isosexual precocity (precocious puberty with phenotypically-appropriate secondary sexual characteristics), macromastia (excessively large breasts), an enlarged uterus, menstrual irregularities, and, similarly to males, accelerated bone maturation and short final height. Of seven females described in one report, three (43%) had macromastia. Pubertal breast hypertrophy in association with AEXS has been described in two young girls.Fertility, though usually affected to one degree or another—especially in males—is not always impaired significantly enough to prevent sexual reproduction, as evidenced by vertical transmission of the condition by both sexes. Cause
The root cause of AEXS is not entirely clear, but it has been elucidated that inheritable, autosomal dominant genetic mutations affecting CYP19A1, the gene which encodes aromatase, are involved in its etiology.