Other research indicate that this condition could be due to immunological changes, such as the reduction of T helper 1 immune cells and the increase in T helper 2 immune cells that occur specifically when pregnant. However, there is not enough evidence to clearly support these claims. Although the pathophysiology of pruritic folliculitis of pregnancy is currently unknown, it has not been significantly linked to harm to either mother or baby. Moreover, this condition resolves after pregnancy and does not affect the development of the baby or recovery of the mother after delivery. Suspected risk factors
There are currently no studies into the etiology behind pruritic folliculitis specifically in pregnancy; however, suspected risk factors include: 

Dry skin
Genetics affecting hormone production
Poor personal hygiene 
Family history of pruritus in pregnancy
Family history of eczema, hay fever, or asthma
Pruritus while taking contraceptive pill prior to pregnancy

Signs and Symptoms
The signs and symptoms of pruritic folliculitis of pregnancy include: redness of the skin, small red bumps that surrounds a hair follicle, and red bumps that are filled with pus "that usually appear first on the abdomen and may spread to the chest, upper portion of the back, shoulders, arms, and thighs" and it occurs during the second or third trimester of pregnancy. These symptoms are typically "mildly pruritic or asymptomatic" lasting between one week to several months. However, symptoms usually self-relieves spontaneously within one month after birth.
After using H&E, hematoxylin and eosin, to stain the samples, the researchers only found some inflammatory cells like neutrophils, monocytes, lymphocytes, and eosinophils. In four of the samples, immunofluorescence microscopy, where fluorescent antibodies bind to a protein of interest and the expression levels are observed through microscopy, was used but there were no signs of immunoglobulins such as IgG, IgM, IgA or C3 found. Since the first description of this condition, there were very few case reports after, indicating the infrequency of pruritic folliculitis. This was also shown by a prospective study that was conducted in 1994 by Roger et al. that concluded with one individual out of 3,192 pregnant mothers (0.03%) had symptoms which were consistent with the diagnosis of pruritic folliculitis. Pathophysiology
Folliculitis, by itself, is a common inflammation process of hair follicles in response to infection or damage to the hair follicles. This inflammatory response can be caused by bacteria, fungi, viruses, or simply ingrown hair. However, pruritic folliculitis of pregnancy is different in that it only occurs in pregnant individuals and during the second or third trimester of pregnancy. There is no clear mechanism in how pruritic folliculitis of pregnancy develops. Because this is a rare condition, there is still currently not enough research to study the cause of it. Some research suggest that this condition may be due to hormone level imbalance during pregnancy .