What is Keratosis Pilaris? Is it a condition to be worried? Is it seen more in children? How does Keratosis Pilaris manifest on the skin, and how do we differentiate it from other conditions? Let us explore this in the article.

What do you mean by keratosis pilaris (KP)

Keratosis Pilaris is a common variant skin condition. We can observe tiny, rough bumps on the arms or legs. The reason behind this is the plugging of hair follicles with keratin, a protein produced in the skin. It starts in early childhood and progresses during the teenage years. This condition is harmless and is associated with other conditions like eczema, dry skin, obesity, diabetes, malnutrition, and genetic conditions like Down syndrome and Noonan syndrome. This condition improves over time, and there are various treatments like moisturisers, exfoliants, anti-inflammatory medications, light therapy, and laser treatments.

Prevalence and affected population

Keratosis Pilaris(KP) is seen in 50 % of children and 40% of the adult population. Since this condition is not reported by everyone, its actual prevalence might be higher than the calculated percentage.²

As per the survey in the UK in the year 1994, the occurrence was higher in the first decade of life, and then it gradually decreased with age. On the contrary, many reports say that it occurs at any age and can stay through adulthood. Other reports also said that the condition improves in summer and worsens in winter due to dry weather.

Overall, very little documentation of Keratosis Pilaris exists on the occurrence, pattern, aggravating factors, and seasonal tendency.

Clinical presentation of keratosis pilaris

It appears as spiny, Keratotic papules approximately 1mm in diameter, each containing brittle, coiled hairs. Papules are grouped or scattered and might involve redness. They can cause hyperpigmentation and pitted scars.

Subtypes of keratosis pilaris

Papules that have redness surrounding them are called Keratosis Pilaris Rubra(KPR). Papules that are greyish-white and have no redness are called Keratosis Pilaris Alba. Later, when the pinhead papules plug shed, it is known as Keratosis Pilaris Atrophicans (KPA). Examples of patients with pitted scars and loss of hair are observed in KPA.² 

Keratosis Pilaris is mostly seen on the upper arms, thighs, and buttocks. It might affect the face and trunk.  Because of the stippled appearance of the skin, it is also known as “gooseflesh” or “chicken skin.”.²   

What are the clinical steps to make a diagnosis?

A complete history and physical examination are essential in making a diagnosis of keratosis pilaris. The onset of symptoms of skin papules, their appearance, location, symptoms, and the concern of the affected individual are all taken into consideration.¹

During the physical examination, we can observe that the papules are small, rough-surfaced, skin colored, follicular papules, with or without redness. Keratosis pilaris rubra is more widespread than keratosis pilaris. The papules do not hurt or itch. It occurs on the outer surface of the upper arms, buttocks, and thighs. The other parts of its occurrence are on the trunk of the body, face, and ends of the limbs. The primary physician or the dermatologist can observe lots of small, inflamed papules around hair follicles in the affected areas. 

Furthermore, dermatoscopic methods can be used to help in diagnosis. Abnormalities of hair follicles can be seen through dermatoscopy. Hair shafts might be thin, short, coiled, or embedded.⁵ In addition, scaling and redness of the skin can also be observed. It does not require a biopsy.

Overall, people with keratosis pilaris seek medical care not due to the discomfort of multiple papules but because of the appearance of the papules on the skin.⁶

How do we differentiate keratosis pilaris from other skin conditions like folliculitis, atopic dermatitis, and lichen spinulosus

The causative factor of Keratosis pilaris is the buildup of Keratin. It is seen in young children and people below 30 years.. These papules are small, dry, and rough. They do not hurt or itch. Upper arms, thighs, and buttocks are the common sites where it occurs.. These conditions usually worsen in the winter. The bumps appear like sandpaper, causing rough skin. Furthermore, these might occur along with genetic diseases or skin conditions like atopic dermatitis.

Folliculitis

It is a skin lesion with small red papules around the hair follicles. The reason might be due to bacterial inflammation or blockage around the hair follicle. The primary reason for inflammation is the bacteria Staphylococcus aureus. Gram-negative bacteria, fungi, Viruses, parasites, medications, patients who are immunocompromised, like those with HIV and having low CD4 counts, and other unknown reasons might also be the reasons for the inflammation.⁷ The affected individuals can experience itchiness and soreness.

The papules are grouped around the hair follicles. They are inflamed and filled with pus. These pus-filled blisters break open, they are itchy, and have all the signs of inflammation. Physical signs play an important role in diagnosing folliculitis. Microscopic examination is done by scraping the affected skin. Biopsy and swab culture of the skin are also performed to check for the infection.

Proper hygiene is very important to cure and prevent its recurrence in folliculitis. In most cases, it will resolve by itself. Most severe cases require antibiotics, antifungal, or anti-parasitic agents. Patients should keep warm compresses for 15 minutes. They should repeat it several times daily.

Atopic dermatitis

Atopic dermatitis is a chronic skin condition seen in infants and children. The symptoms are reduced completely by their teenage years. However, some of their symptoms might continue through their teenage and adult years. The risk for developing atopic dermatitis might be higher if there is a familial history of atopic dermatitis, hay fever, or asthma.¹⁰

Itching is the most frequent symptom of this condition. The other conditions are red, dry patches on the skin, and rashes that may ooze clear fluid and bleed when scratched. The affected part of the skin gets thickened and hardened, and can be seen in different locations of the body. It might be seen in the older location or arise from a new location.

Health care specialists should take patients' histories while diagnosing atopic dermatitis. Consideration of the following factors is essential. The appearance of the lesion and its location. The severity of itchiness, depending if it keeps the patient awake at night. Familial history of atopic triad, contact allergens, the presence of factors that trigger, including allergens, dust mites, animal dander, taking hot showers, sweating, soaps, fragrances, hypersensitivity to food, and synthetic factors like polyester. 

Evaluation of lesions is also done depending on the location in each age group. Its association with keratosis pilaris also helps in diagnosis. The biopsy results show an eczematous pattern. Fluorescent enzyme immunoassays or skin prick testing can be used to detect IgE antibodies for specific allergens.  

Lichen spinulosus

Lichen spinulosus is a clinically characteristic variant of Keratosis pilaris. It is also called keratosis spinulosa and can occur on any part of the body. These can be single papules or multiple-minute follicular papules with a horny spine at the centre of the papule.

It is seen in children, adolescents, and young adults, and most cases occur during adolescence. It has an abrupt onset, and there are no other signs or symptoms. The papules appear continuously or in crops. They are small and rough and spread very fast to affect large areas of skin. The patches are in different sizes, ranging from 2 to 5 cm in diameter.¹² They are distributed symmetrically and are seen on elbows, knees, buttocks, and trunk. The lesions feel like a nutmeg grater(sandpaper). It might itch mildly.

There are no specific labs or tests required for diagnosis. It can be evaluated with observation. The causative factors for lichen spinulosus are unknown. It is not associated with any systemic disorders or genetic conditions. This condition seems to recur within 2 years. In many cases, it has persisted for decades with recurrence.

FAQ’s

What are the common cutaneous manifestations of Acne Vulgaris?

  It manifests with papules, pustules, or nodules mainly on the face. The upper arms, trunk, and back are the other locations where we can sit. It is associated with numerous sebaceous glands.

What are comedones?

Comedones are non-inflammatory lesions of acne. Whiteheads and blackheads are the two types. They are not associated with inflammation.

Is Acne Vulgaris referred to by different names?

It's also referred to as pimples, acne, blackheads, Zits, and breakouts.

What are the bacteria that trigger Acne Vulgaris?

Acne Vulgaris is triggered at the time of adolescence by Culti Bacterium acnes. It is the cause of the inflammatory response in acne.

What do you mean by atopic triad?

It is a group of three allergic conditions: atopic dermatitis, hay fever, and asthma.

What is the other name for ichthyosis vulgaris?

As the dead skin does not shed, it deposits in a similar pattern to a fish scale. Therefore known as fish scale disease or Ichthyosis vulgaris.

Summary

Overall, Keratosis pilaris is a common skin condition. It is seen in childhood and diminishes before the age of 30. It is primarily visible on the outer surface of arms, thighs, and buttocks. This skin condition might worsen during winter. It can easily be diagnosed through Physical examination. People seek treatment because of the appearance and not due to discomfort.