Patterned Acquired Hypertrichosis

Patterned acquired hypertrichosis is a medical term that refers to the abnormal excessive growth of hair in a specific pattern or distribution on the body. This condition can be localized or generalized, and it may affect men, women, and children. The term “acquired” implies that the hypertrichosis developed after birth, rather than being present at birth (congenital). In patterned acquired hypertrichosis, excessive hair growth occurs in specific areas or follows a particular distribution on the body, unlike generalized hypertrichosis, where hair growth is excessive all over the body.


Acquired hypertrichosis differs from congenital hypertrichosis, which is present at birth or develops during infancy. The main causes of patterned acquired hypertrichosis can be classified into several categories:

  1. Endocrine disorders: Hormonal imbalances or endocrine disorders can cause patterned hypertrichosis. Common endocrine disorders associated with this condition include polycystic ovary syndrome (PCOS), Cushing’s syndrome, and adrenal or ovarian tumors. These disorders can lead to an increase in androgen (male hormone) levels in the body, stimulating hair growth.
  2. Medications: Certain medications can cause patterned hypertrichosis as a side effect. Some of these medications include minoxidil, corticosteroids, cyclosporine, and phenytoin. The hair growth may resolve once the medication is discontinued.
  3. Nutritional deficiencies: A deficiency in certain vitamins and minerals, such as biotin, zinc, and vitamin D, may lead to acquired hypertrichosis. Ensuring a balanced diet and addressing any nutritional deficiencies can help manage hair growth.
  4. Dermatological conditions: Skin disorders, such as lichen planus or dermatomyositis, can cause localized hair growth. Treating the underlying skin condition may help resolve the associated hypertrichosis.
  5. Tumors: Some tumors, benign or malignant, can cause localized hypertrichosis due to the pressure they exert on adjacent tissues or the secretion of hormones that promote hair growth.
  6. Inflammatory or autoimmune conditions: In some cases, inflammatory or autoimmune conditions like lupus erythematosus or scleroderma may lead to acquired hypertrichosis. Addressing the underlying condition may help to manage the excessive hair growth.
  7. Post-injury or post-inflammatory hypertrichosis: Trauma or inflammation of the skin, such as burns or injury, can cause hair to grow excessively in the affected area. This can be temporary or permanent, depending on the severity of the injury and the individual’s response to healing.

It is important to note that the causes of patterned acquired hypertrichosis can be complex and multifactorial.


The main symptoms of Patterned acquired hypertrichosis include:

  1. Excessive hair growth: Individuals with PAH experience an abnormal increase in hair growth, which may vary in density and distribution. This excessive hair growth typically occurs in non-androgen-dependent areas, meaning it does not follow the usual pattern of male or female hair growth.
  2. Distinct patterns: The hair growth in PAH follows specific patterns, which can include linear, whorled, or patchy distribution. The patterns may be symmetrical or asymmetrical and can involve any part of the body.
  3. Hair type and color: The excess hair growth in PAH can involve various hair types, such as vellus (soft, fine, and short) or terminal (thicker, longer, and darker) hairs. The hair color may be similar to or different from the person’s natural hair color.
  4. Sudden onset: The onset of excessive hair growth in PAH can be sudden or gradual. In some cases, the hair growth may be triggered by an external factor, such as medication or an underlying medical condition.
  5. Associated factors: PAH can be associated with other medical conditions, such as autoimmune diseases, endocrine disorders, or malignancies. Identifying and addressing these underlying conditions may help manage the symptoms of PAH.
  6. No other physical abnormalities: Individuals with PAH typically do not have other physical abnormalities or developmental delays associated with their excessive hair growth.


Details on the main diagnosis of patterned acquired hypertrichosis:

  1. Medical History: The diagnostic process begins with obtaining a thorough medical history from the patient. This may include asking about the age of onset, duration, and progression of the excessive hair growth, as well as any underlying medical conditions or medications that may be contributing to the hypertrichosis.
  2. Physical Examination: A detailed physical examination is crucial for evaluating the pattern and extent of hair growth. The examining physician may assess the hair density, distribution, and thickness to determine the severity of the condition.
  3. Classification: Patterned acquired hypertrichosis can be classified into various types, such as localized or generalized, and further subtypes based on specific patterns or distribution of hair growth. Identifying the correct classification helps in understanding the possible causes and choosing appropriate treatments.
  4. Laboratory Tests: In some cases, blood tests may be performed to rule out hormonal imbalances, such as thyroid dysfunction or polycystic ovary syndrome (PCOS), which could be contributing to the excessive hair growth. Additionally, other tests may be conducted to rule out underlying systemic diseases.
  5. Imaging Studies: If an underlying medical condition is suspected, imaging studies such as ultrasounds, CT scans, or MRIs may be ordered to identify any abnormalities that may be causing the hypertrichosis.
  6. Biopsy: In some cases, a skin biopsy may be performed to examine the hair follicle and surrounding skin tissue under a microscope. This can help determine if there are any structural or pathological abnormalities contributing to the hair growth.
  7. Differential Diagnosis: The physician must also consider and rule out other conditions that may cause excessive hair growth, such as hirsutism, congenital hypertrichosis, or syndromes associated with hypertrichosis.


The main goal of treatment is to identify and address the underlying cause, in addition to managing the cosmetic symptoms.

  1. Identify and address underlying causes: a. Hormonal imbalances: If PAH is caused by hormonal imbalances (such as in polycystic ovary syndrome or Cushing’s syndrome), treatment may involve hormone therapy, medications, or lifestyle changes to help regulate hormone levels. b. Medications: If the condition is triggered by a medication, the healthcare provider may consider adjusting the dosage or changing the medication. c. Medical conditions: In cases where PAH is caused by an underlying medical condition (e.g., cancer, autoimmune disorders), treating the primary condition may help alleviate the hypertrichosis symptoms.
  2. Cosmetic management: a. Hair removal: Temporary hair removal methods such as shaving, waxing, plucking, or depilatory creams can be used to manage the appearance of excessive hair. These methods may need to be repeated regularly, as hair growth will continue. b. Laser hair removal: This involves using a laser to target and destroy the hair follicles, resulting in a significant reduction in hair growth. Multiple sessions are usually required, and the results may vary depending on the individual’s hair and skin color. This method offers longer-lasting results compared to temporary hair removal methods. c. Electrolysis: This is another long-term hair removal option where an electric current is applied to individual hair follicles to destroy them. It can be a more time-consuming and costly process, but it can provide permanent hair removal.
  3. Psychological support: As PAH can cause significant psychological distress, counseling or support groups may be helpful for individuals coping with the condition.

It is essential to consult a healthcare professional for an accurate diagnosis and tailored treatment plan, as the specific treatment approach will depend on the individual’s specific situation and the underlying cause of the PAH.