What is Confluent and Reticulated Papillomatosis?

Confluent and reticulated papillomatosis (CRP), also known as Gougerot-Carteaud syndrome, is a condition caused by abnormal skin cell development. It was first identified by Gougerot and Carteaud.

CRP shows up as symptom-free darker colored bumps on the upper body and neck of teenagers and young adults. These bumps sometimes merge together into bigger patches. The specific cause of CRP has been a topic of discussion and isn’t totally clear yet.

At first, it was thought to be caused by an infection from a particular kind of yeast known as Malassezia furfur. However, research has shown that not all people with CRP are infected with this yeast. Nowadays, it’s believed that an infection from Dietzia papillomatosis, a type of bacteria, might be the cause.

Other potential causes could be diabetes, obesity, exposure to ultraviolet light, a disease called amyloidosis, or an overproduction of a protein in skin cells known as keratin-16.

The first choice for treatment is a medication called minocycline. The bumps may need 12 to 39 months to completely disappear. Additionally, there’s a 13.8% to 15.4% chance that the condition may come back after being treated.

Figure 1 PRURIGO NODULARIS involving the limbs of a 65-year old lady: A,
Clinical Image showing the typical hyperpigmented papules and nodules over the
right upper extremity with excoriations; B, Polarized dermoscopic image from a
papule showing an irregularly-shaped large reddish-brown clod with localized
white structureless area (white arc), with interspersed red and brown colored
dots and pigmented granules [Escope, USB Videodermoscope, 30X; Timpac Healthcare
Pvt. Ltd., New Delhi]; and C, On histopathology from a nodule the epidermis is
showing marked compact orthokeratosis, thickened granular layer, and irregular
epidermal hyperplasia. The papillary dermis is thickened with papillomatosis and
thickened bundles of collagen in vertical array, with increased number of thick
walled capillaries and sparse superficial perivascular lymphocytic infiltrate
[Hematoxylin & eosin, 400X]
Figure 1 PRURIGO NODULARIS involving the limbs of a 65-year old lady: A,
Clinical Image showing the typical hyperpigmented papules and nodules over the
right upper extremity with excoriations; B, Polarized dermoscopic image from a
papule showing an irregularly-shaped large reddish-brown clod with localized
white structureless area (white arc), with interspersed red and brown colored
dots and pigmented granules [Escope, USB Videodermoscope, 30X; Timpac Healthcare
Pvt. Ltd., New Delhi]; and C, On histopathology from a nodule the epidermis is
showing marked compact orthokeratosis, thickened granular layer, and irregular
epidermal hyperplasia. The papillary dermis is thickened with papillomatosis and
thickened bundles of collagen in vertical array, with increased number of thick
walled capillaries and sparse superficial perivascular lymphocytic infiltrate
[Hematoxylin & eosin, 400X]

What Causes Confluent and Reticulated Papillomatosis?

It was once believed that a yeast called Malassezia furfur was the cause of a skin condition known as confluent and reticulated papillomatosis. However, recent research hasn’t consistently found this yeast in patients with the condition. Now, it is being suggested that a type of bacteria named Dietzia papillomatosis could be the culprit.

Apart from infectious causes, there are also non-infectious causes that might lead to this skin condition. These include things like diabetes, obesity, exposure to ultraviolet light, a rare disease called amyloidosis, and a genetic mutation known as K16.

Sometimes people with this skin condition also have diabetes or are overweight. This could be related to the fact that high levels of insulin, which can occur in these conditions, can promote skin cell growth and prevent the natural death of these cells. Studies have found that if a person’s weight or diabetes is well-controlled, the skin condition can improve. This suggests that insulin and weight changes are indeed connected to this condition.

Ultraviolet (UV) light might cause confluent and reticulated papillomatosis because it can affect the process that produces a pigment in our skin, and it can also cause a temporary increase in skin cell growth. Amyloidosis, a condition where a certain protein builds up in the body, might be another cause as some patients with the skin condition were found to have these protein deposits.

In some families, the skin condition seems to run in the family. This might be due to a genetic factor – specifically an overproduction of a protein called keratin-16.

Risk Factors and Frequency for Confluent and Reticulated Papillomatosis

Confluent and reticulated papillomatosis is a condition that can occur all around the world, but it’s more common in people who are Caucasian. Several studies have looked into who is typically affected by this condition:

  • A study by the Mayo Clinic found that the condition usually starts around the age of 15, although it can occur in anyone from 8 to 32 years old. Males are slightly more likely to get it than females, with a ratio of 1.4 to 1.
  • In Japan, another study found that the average age when the condition starts is 17, with a range of 3 to 30 years. Again, males are slightly more likely to get it.
  • Lastly, a study in Singapore reported the average onset age to be around 29, anywhere between 16 to 55 years. They found a stronger male bias, with a ratio of 2.6 to 1.

Signs and Symptoms of Confluent and Reticulated Papillomatosis

Confluent and reticulated papillomatosis is a skin condition that usually doesn’t cause noticeable symptoms, but in some cases, it can lead to itching. This condition makes the skin appear different, with changes such as 5 mm brown to dark spots and small raised areas that can merge together to form larger patches. These patches often have a pattern that looks like a network around the edges. The skin can feel velvet-like or wart-like in some areas. The small raised areas can sometimes show changes like scaling, thickening, or thinning of the skin. This condition mainly affects the upper body and the area under the arms, but it can also show up on the shoulders, arms, and the inner parts of the elbow and knee. In rare cases, it can even appear on the forehead.

Figure 1 PRURIGO NODULARIS involving the limbs of a 65-year old lady: A,
Clinical Image showing the typical hyperpigmented papules and nodules over the
right upper extremity with excoriations; B, Polarized dermoscopic image from a
papule showing an irregularly-shaped large reddish-brown clod with localized
white structureless area (white arc), with interspersed red and brown colored
dots and pigmented granules [Escope, USB Videodermoscope, 30X; Timpac Healthcare
Pvt. Ltd., New Delhi]; and C, On histopathology from a nodule the epidermis is
showing marked compact orthokeratosis, thickened granular layer, and irregular
epidermal hyperplasia. The papillary dermis is thickened with papillomatosis and
thickened bundles of collagen in vertical array, with increased number of thick
walled capillaries and sparse superficial perivascular lymphocytic infiltrate
[Hematoxylin & eosin, 400X]
Figure 1 PRURIGO NODULARIS involving the limbs of a 65-year old lady: A,
Clinical Image showing the typical hyperpigmented papules and nodules over the
right upper extremity with excoriations; B, Polarized dermoscopic image from a
papule showing an irregularly-shaped large reddish-brown clod with localized
white structureless area (white arc), with interspersed red and brown colored
dots and pigmented granules [Escope, USB Videodermoscope, 30X; Timpac Healthcare
Pvt. Ltd., New Delhi]; and C, On histopathology from a nodule the epidermis is
showing marked compact orthokeratosis, thickened granular layer, and irregular
epidermal hyperplasia. The papillary dermis is thickened with papillomatosis and
thickened bundles of collagen in vertical array, with increased number of thick
walled capillaries and sparse superficial perivascular lymphocytic infiltrate
[Hematoxylin & eosin, 400X]

Testing for Confluent and Reticulated Papillomatosis

The diagnosis of certain skin disorders is largely based on the clinical symptoms observed by the doctor. To make sure that the diagnosis is correct and to exclude other conditions, a skin biopsy may be carried out. This involves taking a small sample of skin for further investigation. A technique called dermoscopy can be used to examine the skin more closely and can show brown coloration with white flakes and a grooved pattern.

For one specific condition, known as confluent and reticulated papillomatosis, experts have proposed specific factors that doctors should look for. These include:

  • Visibly scaly brown spots and patches, some of which might resemble a net or have a knobbly texture
  • The appearance of these symptoms on the upper body or neck
  • Samples of the affected skin testing negative for fungal infection
  • Having no improvement after being treated with antifungal drugs
  • A good response to treatment with minocycline, a type of antibiotic

In 2014, another group of experts suggested a slight change in the last three points, saying that the symptoms could also be found in the skin folds, and the significant improvement can also be noted with the use of antibiotics generally.

Additionally, the doctor might consider other skin disorders that show similar symptoms like acanthosis nigricans, tinea versicolor, Dowling-Degos disease, Galli-Galli disease, dyskeratosis congenita, prurigo pigmentosa, terra firma-forme dermatosis, and Darier disease.

Treatment Options for Confluent and Reticulated Papillomatosis

Confluent and reticulated papillomatosis is a skin condition that doesn’t usually cause symptoms, but its treatment can help with emotional wellbeing and improving the skin’s appearance. The primary treatments include antimicrobial medicines.

Antibiotics are the first choice for treatment. Minocycline, taken twice a day for six weeks, is often effective with few side effects. However, some possible side effects could include allergic reactions, drug-induced lupus, skin color changes, and balance issues. It’s important to note that minocycline can’t be used during pregnancy. Azithromycin is an alternative that’s safe for use during pregnancy. Taken daily for two weeks or three times weekly for three weeks, Azithromycin can help improve the skin’s appearance. Other effective antibiotics include oral clarithromycin and erythromycin. They help not only by killing bacteria but also by reducing inflammation in the skin.

Antifungal medicines are used due to a past theory that a type of yeast might cause this skin condition. Using a selenium sulfide lotion daily for three weeks, followed by weekly use for another three weeks, has been shown to be effective. However, the effect could be due to the lotion’s ability to break down skin cells rather than its antifungal properties. Other antifungal medicines have had some success, but the condition often returns after treatment.

Finally, other treatments like retinoids (vitamin A medicines) can be effective. But antibiotics like minocycline and azithromycin are safer and usually preferred. Creams and ointments containing retinoids, urea, calcipotriol, and tacrolimus have also been successful in treating this skin condition. In some cases, oral contraceptives have been used successfully, such as in a patient with polycystic ovarian syndrome.

  • Acanthosis nigricans: a condition causing dark, thickened skin in certain areas.
  • Achlorhydria: a disorder where the stomach produces little or no acid.
  • Dermatopathia pigmentosa reticularis: a rare skin disorder that leads to network-like pigmentation on the skin.
  • Epidermal nevus syndrome: a condition where benign skin growths are accompanied by abnormalities in the brain, eyes, or other body parts.
  • Epidermodysplasia verruciformis: a rare skin disorder leading to increased risk of skin cancer.
  • Keratosis folicularis: also known as Darier’s disease, it causes greasy bumps on the skin.
  • Pityriasis Rubra pilaris: a rare skin disorder leading to constant shedding of the skin.
  • Pseudoatrophoderma colli: a skin disorder causing the neck’s skin to appear thin and wrinkled.
  • Seborrheic keratosis: a type of harmless skin growth that appears during adulthood.
  • Syringoma: harmless sweat gland tumors, usually found clustered on eyelids.
Frequently asked questions

Confluent and reticulated papillomatosis (CRP), also known as Gougerot-Carteaud syndrome, is a condition caused by abnormal skin cell development.

Confluent and reticulated papillomatosis is a condition that can occur all around the world, but it's more common in people who are Caucasian.

Signs and symptoms of Confluent and Reticulated Papillomatosis include: - Skin changes such as 5 mm brown to dark spots - Small raised areas that can merge together to form larger patches - Patches with a network-like pattern around the edges - Velvet-like or wart-like texture in some areas - Changes like scaling, thickening, or thinning of the skin in the raised areas - Mainly affects the upper body and the area under the arms - Can also show up on the shoulders, arms, and the inner parts of the elbow and knee - In rare cases, it can even appear on the forehead

There are both infectious and non-infectious causes of Confluent and Reticulated Papillomatosis. Infectious causes include a type of bacteria called Dietzia papillomatosis, while non-infectious causes include diabetes, obesity, exposure to ultraviolet light, amyloidosis, and a genetic mutation known as K16.

The doctor needs to rule out the following conditions when diagnosing Confluent and Reticulated Papillomatosis: - Acanthosis nigricans - Tinea versicolor - Dowling-Degos disease - Galli-Galli disease - Dyskeratosis congenita - Prurigo pigmentosa - Terra firma-forme dermatosis - Darier disease - Achlorhydria - Dermatopathia pigmentosa reticularis - Epidermal nevus syndrome - Epidermodysplasia verruciformis - Keratosis folicularis - Pityriasis Rubra pilaris - Pseudoatrophoderma colli - Seborrheic keratosis - Syringoma

The types of tests that may be needed for Confluent and Reticulated Papillomatosis include: - Skin biopsy: A small sample of skin is taken for further investigation. - Dermoscopy: This technique allows for a closer examination of the skin and can reveal brown coloration with white flakes and a grooved pattern. - Fungal testing: Samples of the affected skin may be tested to rule out fungal infection. - Response to treatment: The doctor may consider the response to treatment with antibiotics, such as minocycline, as a diagnostic factor. - Consideration of other skin disorders: The doctor may also consider other skin disorders that show similar symptoms to Confluent and Reticulated Papillomatosis.

Confluent and Reticulated Papillomatosis is treated primarily with antimicrobial medicines. The first choice for treatment is antibiotics, such as minocycline, which is taken twice a day for six weeks. This medication is often effective with minimal side effects, although possible side effects include allergic reactions, drug-induced lupus, skin color changes, and balance issues. It is important to note that minocycline cannot be used during pregnancy. Azithromycin is a safe alternative for use during pregnancy, taken daily for two weeks or three times weekly for three weeks. Other effective antibiotics include oral clarithromycin and erythromycin, which not only kill bacteria but also reduce inflammation in the skin. Antifungal medicines, such as selenium sulfide lotion, have also been used, although their effectiveness may be due to their ability to break down skin cells rather than their antifungal properties. Other treatments like retinoids, creams, and ointments containing various ingredients have also shown success in treating this skin condition.

When treating Confluent and Reticulated Papillomatosis, the following side effects may occur: - Allergic reactions - Drug-induced lupus - Skin color changes - Balance issues

The prognosis for Confluent and Reticulated Papillomatosis is generally good, with the bumps typically disappearing after 12 to 39 months of treatment with the medication minocycline. However, there is a 13.8% to 15.4% chance that the condition may come back after being treated.

A dermatologist.

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