This is a serious topic. Before talking about this topic, let’s talk briefly about freckles.

Freckles are generally not present at birth, and often appear within 3 years of birth. Sun-induced increased melanin synthesis and increased transfer of complete melanosomes from melanocytes to keratinocytes contribute to the pigmentation of freckles.

Freckles only occur on light-exposed areas, mainly including cheeks, extended sides of arms, and upper chest and back, and do not appear on mucous membranes. The skin lesions have clear borders and are round, oval or irregular in shape. Diameter 1~3mm, can also be slightly larger. Depending on the intensity of sun exposure, the color can range from light brown to dark brown, but will not be darker than sunspots and junctional nevus. The number and extent of skin lesions can gradually expand and merge with each other.

As age increases, skin lesions can gradually decrease. Freckles are benign lesions and have no tendency to become malignant. Reduce sun exposure, and pay attention to the use of sunscreen, hats, clothing and other sun protection; topical retinoic acid drugs and hydroquinone can alleviate the symptoms.

However, when dermatologists encounter people with freckle-like dark brown or black pinpoint mung bean-sized spots around their mouths, lips and orbits, they will almost always use condoms even on the road or subway. Carefully ask about the medical history, such as when the disease occurred and whether there are any other discomforts. Because as mentioned before, freckles do not grow on the mucosa. The dark spots that grow on the perioral oral mucosa are likely to be pigmentation-polyposis syndrome, also called perioral pigmentation intestinal polyp syndrome, perioral Sunspot disease or Poitz-Yeager syndrome. A disease of unknown etiology, it is an inherited polyposis syndrome caused by mutations in the STK11 gene and is inherited in an autosomal dominant manner. There is no difference in the incidence between men and women. Both genders can be affected. The disease occurs at birth or in early childhood, and occasionally occurs in adulthood. The rash is mainly distributed around the mouth, lips (especially the lower lip),

oral mucosa,

and can also be found on the ends of fingers (toes), palms and insteps. They are dark brown or black spots the size of a pinhead or a mung bean or larger. The number varies, ranging from more than ten to more than ten.

Some only have mucosal pigment spots without skin manifestations. The number, size, and distribution of pigmented spots have nothing to do with gastrointestinal lesions. These pigmentations are usually observed before the age of 5 years and can also be seen on the buccal mucosa, around the eyes, nostrils, and soles of the feet as dark blue, brown, or black spots. Pigmentation may slowly fade after puberty, but pigmentation of the buccal mucosa generally persists into adulthood.

The size and color of pigmented spots are not affected by sunlight (freckles are closely related to sun exposure and only occur in light-exposed areas. Due to different intensity of sun exposure, the color ranges from light brown to dark brown). Polyps appear later than pigmented spots. Before the age of 10, patients may gradually develop symptoms related to gastrointestinal polyps such as gastrointestinal bleeding, iron deficiency anemia, abdominal pain caused by intussusception, intestinal obstruction, ulcers or ischemia. These low-risk gastrointestinal polyps can occur anywhere in the gastrointestinal tract, most commonly in the jejunum, but can also occur in other parts of the digestive system.

The average age at diagnosis of pigmentation-polyposis syndrome is 23 years old, and the first manifestations of patients are often complications of intussusception and intestinal obstruction caused by gastrointestinal polyps. Up to 69% of patients develop small intestinal intussusception. The age of first onset is usually between 6 and 18 years old. It can affect the entire gastrointestinal tract, mainly the small intestine, especially the jejunum and ileum. Polyps are often multiple and vary in size, ranging from as small as a needle to as large as a chicken egg. The canceration rate of polyps is 3% to 25%. Pigmentation-polyposis syndrome can also be accompanied by nail dystrophy, scoliosis, ovarian cysts, skin telangiectasia, congenital heart disease, etc. The skin manifestations of pigmentation-polyposis syndrome are different from freckles and sunspots. Freckles are mainly distributed on the face and do not involve the mucous membrane. The symptoms are aggravated after sun exposure; the sunspots are sparsely distributed and scattered, and the mucosa is generally not affected.

Preventing and treating pigmented spots does not require treatment. For cosmetic purposes, intense pulsed light technology and laser can be used to treat skin and mucous membrane pigmentation. 694mm ruby ??laser treatment can be used when necessary. The treatment of polyps depends on the symptoms. If the symptoms are not obvious, treat them symptomatically. If the symptoms are obvious, such as acute abdomen or suspected cancer, selective intestinal segmental resection should be performed. Because gastrointestinal polyps are often multiple and widely distributed, complete resection is impossible, so preventive intestinal segmental resection is of little significance.