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Author:

Gary W. Cole, MD, FAAD

Gary W. Cole, MD, FAAD

Dr. Cole is board certified in dermatology. He obtained his BA degree in bacteriology, his MA degree in microbiology, and his MD at the University of California, Los Angeles. He trained in dermatology at the University of Oregon, where he completed his residency.

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Author:

Nili N. Alai, MD, FAAD

Nili N. Alai, MD, FAAD

Dr. Alai is an actively practicing medical and surgical dermatologist in south Orange County, California. She has been a professor of dermatology and family medicine at the University of California, Irvine since 2000. She is U.S. board-certified in dermatology, a 10-year-certified fellow of the American Academy of Dermatology, and Fellow of the American Society of Mohs Surgery.

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Medical Editor:

William C. Shiel Jr., MD, FACP, FACR

William C. Shiel Jr., MD, FACP, FACR

Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

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In this Article

• Keratosis pilaris facts
• What is keratosis pilaris (KP)?
• Who gets keratosis pilaris?
• What is the prognosis of patients with keratosis pilaris?
• Does keratosis pilaris affect the entire body?
• What does keratosis pilaris look like?
• What causes keratosis pilaris?
• How is keratosis pilaris diagnosed?
• Is keratosis pilaris curable?
• Is keratosis pilaris contagious?
• What are possible complications of keratosis pilaris?
• Does diet have anything to do with keratosis pilaris?
• Keratosis pilaris "do's"
• Keratosis pilaris "don'ts"
• Patient Comments: Keratosis Pilaris - Cause
• Find a local Dermatologist in your town
• Keratosis Pilaris Index

The diagnosis of KP is very straightforward and based on a typical skin appearance in areas like the upper arms. A family history of KP is also very helpful since there is a strong genetic component to the condition. The diagnosis is confirmed by the physician's clinical exam.

What else could it be?

Other medical conditions can mimic KP. KP may resemble acne, milia, folliculitis, eczema, atopic dermatitis, facial rosacea, or dry skin (xerosis). KP may also resemble uncommon skin conditions like lichen spinulosus, pityriasis rubra pilaris, phrynoderma (vitamin A deficiency), ulerythema ophryogenes, ichthyosis vulgaris, eruptive vellus hair cysts, keratosis follicularis (Darier disease), Kyrle disease, lichen nitidus, lichen spinulosus, perforating folliculitis, and trichostasis spinulosa.

In India and other countries, a specific condition called erythromelanosis follicularis faciei et colli occurs. This unusual condition has a possible genetic relationship to KP. Erythromelanosis follicularis faciei et colli is characterized by the triad of hyperpigmentation (darker skin color), follicular plugging (blocked hair follicles), and redness of the face and neck.

Are there any lab tests to help diagnose keratosis pilaris?

Since the appearance if keratoses pilaris is easily recognized, specific laboratory tests are not helpful for the diagnosis. Skin biopsy (surgically taking a small piece of skin using local numbing medicine) may be useful in atypical or widespread cases.

What does keratosis pilaris look like under the microscope?

Microscopic examination of the body tissue by a pathologist or dermatopathologist under high magnification is called histopathology or pathology. Histopathology of KP shows mild hyperkeratosis of the epidermis (thickening of the outer layer of skin), hypergranulosis (increase in the special granular cells of the epidermis), and plugging of individual hair follicles. The upper dermis (layer of the skin below the epidermis) may have some microscopic inflammation called mild superficial perivascular lymphocytic inflammatory changes.