4 Things You Need to Know About Reactive Perforating Collagenosis

Many skin conditions can cause itchy bumps to form on your skin, including less well-known conditions like reactive perforating collagenosis. This guide will help you to know whether you have this condition, how it is diagnosed, why it occurs, and how it can be treated. 

What are the signs of reactive perforating collagenosis?

Reactive perforating collagenosis presents as itchy, skin-colored papules with indented centers. These papules can reach sizes of 10 millimeters (0.4 inches) in diameter. At their centers, you'll see a keratinous plug. Keratin is one of the proteins in the outer layer of your skin, and when it forms a plug, it forms a dark core that looks similar to a blackhead. However, unlike blackheads, these plugs are adherent, which means they can't be squeezed out of the lesions.

These lesions are usually seen on the fronts of the arms and legs and the backs of the hands. They can also be seen on the torso and the face, and they may appear in a linear (straight line) pattern. Once the lesions heal, they'll leave scars, so you may have residual scarring and active lesions on your skin at the same time. If you notice these papules or their scars on your skin, see a dermatologist for a diagnosis.

How is reactive perforating collagenosis diagnosed?

To diagnose reactive perforating collagenosis, your dermatologist will need to take a biopsy of the papules. While biopsies are often associated with cancer, don't worry—reactive perforating collagenosis isn't cancerous. Your dermatologist simply needs to remove one of the papules to take a closer look at it under a microscope. Microscopic testing, known as histopathology, is essential for the diagnosis of this condition. Once your diagnosis has been ascertained, you can begin treatment.

Why does reactive perforating collagenosis occur?

This condition occurs when collagen, a protein that makes up your skin, is eliminated from the skin and expelled through the epidermis, which is the outer layer of your skin.

Reactive perforating collagenosis can be either inherited or acquired. When it is inherited, it's caused by genetic abnormalities. Researchers still aren't sure how these abnormalities are passed on, as studies haven't determined a definite inheritance pattern. In some families, the disease follows an autosomal dominant pattern, while in others, it follows an autosomal recessive pattern. Autosomal dominant means that only one of your parents needs to carry the genes in question for you to get the disease, while autosomal recessive means that both of your parents need to carry the abnormal genes for this to happen. More research needs to be done to determine why the inheritance pattern varies between families.

However, this condition isn't always passed down through families; it can also be acquired later in life. This happens as a result of other medical problems that you develop. Both diabetes and chronic kidney disease have been linked to reactive perforating collagenosis, as have other diseases like AIDS, lymphoma, and atopic dermatitis. The disease may also occur as a result of intense scratching, which is associated with a number of dermatological conditions.

How do dermatologists treat the lesions?

Your dermatologist may prescribe topical tretinoin, a medication that's used to treat many skin diseases, including acne. It works by unclogging your pores, which will loosen the keratinous plugs. This treatment works best for small lesions or lesions that are newly developed. If your lesions are large or longstanding, oral isotretinoin will be used instead.

Narrowband ultraviolet-B phototherapy can also be used to treat this condition. This treatment exposes your skin to controlled levels of ultraviolet light, which is reported to be an effective treatment.

If you think you have reactive perforating collagenosis, see a professional at an establishment like Advanced Dermatology Care right away.