Nevi are typically diagnosed clinically with the naked eye or using dermatoscopy. More advanced imaging tests are available for distinguishing melanocytic nevi from melanoma, including computerized dermoscopy and image analysis. The management of nevi depends on the type of nevus and the degree of diagnostic uncertainty. Some nevi are known to be benign, and may simply be monitored over time. Others may warrant more thorough examination and biopsy for histopathological examination (looking at a sample of skin under a microscope to detect unique cellular features). For example, a clinician may want to determine whether a pigmented nevus is a type of melanocytic nevus, dysplastic nevus, or melanoma as some of these skin lesions pose a risk for malignancy. The ABCDE criteria (asymmetry, border irregularity, color variegation, diameter > 6 mm, and evolution) are often used to distinguish nevi from melanomas in adults, while modified criteria (amelanosis, bleeding or bumps, uniform color, small diameter or de novo, and evolution) can be used when evaluating suspicious lesions in children. In addition to histopathological examination, some lesions may also warrant additional tests to aid in diagnosis, including special stains, immunohistochemistry, and electron microscopy. Typically; the nevi which exist since childhood are harmless

The management of a nevus depends on the specific diagnosis, however, the options for treatment generally include the following modalities:

A doctor can diagnose a stork bite with a simple visual inspection. No tests are needed.

Diagnosis is visual with measurement of spot size. The number of spots can have clinical significance for diagnosis of associated disorders such as Neurofibromatosis type I. Greater than or equal to 6 spots of at least 5mm in diameter in pre-pubertal children and at least 15mm in post-pubertal individuals is one of the major diagnostic criteria for NF1.

Café au lait spots can be removed with lasers. Results are variable as the spots are often not completely removed or can come back after treatment. Often, a test spot is treated first to help predict the likelihood of treatment success.

Most stork bites on the face go away completely in about 18 months. Stork bites on the back of the neck usually do not go away.

In general, children with a small isolated nevus and a normal physical exam do not need further testing; treatment may include potential surgical removal of the nevus. If syndrome issues are suspected, neurological, ocular, and skeletal exams are important. Laboratory investigations may include serum and urine calcium and phosphate, and possibly liver and renal function tests. The choice of imaging studies depends on the suspected abnormalities and might include skeletal survey, CT scan of the head, MRI, and/or EEG.

Depending on the systems involved, an individual with Schimmelpenning syndrome may need to see an interdisciplinary team of specialists: dermatologist, neurologist, ophthalmologist, orthopedic surgeon, oral surgeon, plastic surgeon, psychologist.

There is no treatment, but because this is a benign condition with no serious clinical complications, prognosis is excellent.

There is no diagnosis as yet for Cutis verticis gyrata (CVH), but it can generally be found out by self, when the person is applying oil to the scalp or getting the hair fully shaven. The ripples are present either in identical form, mostly in the posterior direction, sometimes horizontally also, but it looks more like the ripples of the brain.

There is no clinical diagnosis for CVG as these cases are rarely seen and is often comorbid with other conditions.

Treatment is by excisional biopsy, wide local excision and possibly sentinel node biopsy. Spread of disease to local lymph nodes or distant sites (typically brain, bone, skin and lung) marks a decidedly poor prognosis.

There is no 'cure' for this condition and currently, medical treatment is limited to plastic surgery with excision of the folds by means of scalp reduction/surgical resection. Scalp subcision has also been suggested as a treatment. Additional suggestions also include injections of a dermal filler i.e. Sculptra (poly-L-lactic acid)

Phakomatosis pigmentokeratotica is a rare neurocutanous condition characterized by the combination of an organoid sebaceous nevus and speckled lentiginous nevus. It is an unusual variant of epidermal naevus syndrome. It was first described by Happle "et al". It is often associated with neurological or skeletal anomalies such as hemiatrophy, dysaesthesia and hyperhidrosis in a segmental pattern, mild mental retardation, seizures, deafness, ptosis and strabismus.

The ICD-10 lists WSN under "other congenital malformations of mouth". It could be classified as a skin condition, or more precisely as a genodermatosis (a genetically determined skin disorder).

Nevus sebaceous was first identified in 1895 by Jadassohn. Sebaceous nevi occur in 1 to 3 of 1000 births, with equal incidence by sex. There is no test to determine whether an individual born with a sebaceous nevus will go on to develop further symptoms of Schimmelpenning syndrome. It has been reported that up to 10% of individuals with epidermal nevi may develop additional syndrome symptoms, but that number appears to be inconsistent with the rarity of the syndrome and may be overstated. Prevalence is unknown, but Epidermal nevus syndrome is listed with the National Organization for Rare Disorders, which defines "rare" as affecting "fewer than 200,000 people in the United States."

There is no cure for this condition. Treatment is supportive and varies depending on how symptoms present and their severity. Some degree of developmental delay is expected in almost all cases of M-CM, so evaluation for early intervention or special education programs is appropriate. Rare cases have been reported with no discernible delay in academic or school abilities.

Physical therapy and orthopedic bracing can help young children with gross motor development. Occupational therapy or speech therapy may also assist with developmental delays. Attention from an orthopedic surgeon may be required for leg length discrepancy due to hemihyperplasia.

Children with hemihyperplasia are thought to have an elevated risk for certain types of cancers. Recently published management guidelines recommend regular abdominal ultrasounds up to age eight to detect Wilms' tumor. AFP testing to detect liver cancer is not recommended as there have been no reported cases of hepatoblastoma in M-CM patients.

Congenital abnormalities in the brain and progressive brain overgrowth can result in a variety of neurological problems that may require intervention. These include hydrocephalus, cerebellar tonsillar herniation (Chiari I), seizures and syringomyelia. These complications are not usually congenital, they develop over time often presenting complications in late infancy or early childhood, though they can become problems even later. Baseline brain and spinal cord MRI imaging with repeat scans at regular intervals is often prescribed to monitor the changes that result from progressive brain overgrowth.

Assessment of cardiac health with echocardiogram and EKG may be prescribed and arrhythmias or abnormalities may require surgical treatment.

There is disagreement as to how cases of KTS should be classified if there is an arteriovenous fistula present. Although several authorities have suggested that the term Parkes-Weber syndrome is applied in those cases, ICD-10 currently uses the term "Klippel–Trénaunay–Weber syndrome".

Superficial spreading melanoma (also known as "superficially spreading melanoma") (SSM) is usually characterized as the most common form of cutaneous melanoma in Caucasians. The average age at diagnosis is in the fifth decade, and it tends to occur on sun-exposed skin, especially on the backs of males and lower limbs of females.

Prognosis varies widely depending on severity of symptoms, degree of intellectual impairment, and associated complications. Because the syndrome is rare and so newly identified, there are no long term studies.

KTS is a complex syndrome, and no single treatment is applicable for everyone. Treatment is decided on a case-by-case basis with the individual's doctors.

At present, many of the symptoms may be treated, but there is no cure for Klippel–Trenaunay syndrome.

Before any treatment of leg telangectasia (spider veins) is considered, it is essential to have duplex ultrasonography, the test that has replaced Doppler ultrasound. The reason for this is that there is a clear association between leg telangectasia (spider veins) and underlying venous reflux. Research has shown that 88-89% of women with telangectasia (spider veins) have refluxing reticular veins close, and 15% have incompetent perforator veins nearby. As such, it is essential to both find and treat underlying venous reflux before considering any treatment at all.

Sclerotherapy is the "gold standard" and is preferred over laser for eliminating telangiectasiae and smaller varicose leg veins. A sclerosant medication is injected into the diseased vein so it hardens and eventually shrinks away. Recent evidence with foam sclerotherapy shows that the foam containing the irritating sclerosant quickly appears in the patient's heart and lungs, and then in some cases travels through a patent foramen ovale to the brain. This has led to concerns about the safety of sclerotherapy for telangectasias and spider veins.

In some cases stroke and transient ischemic attacks have occurred after sclerotherapy. Varicose veins and reticular veins are often treated before treating telangiectasia, although treatment of these larger veins in advance of sclerotherapy for telangiectasia may not guarantee better results. Varicose veins can be treated with foam sclerotherapy, endovenous laser treatment, radiofrequency ablation, or open surgery. The biggest risk, however, seems to occur with sclerotherapy, especially in terms of systemic risk of DVT, pulmonary embolism, and stroke.

Other issues which arise with the use of sclerotherapy to treat spider veins are staining, shadowing, telangetatic matting, and ulceration. In addition, incompleteness of therapy is common, requiring multiple treatment sessions.

Telangiectasias on the face are often treated with a laser. Laser therapy uses a light beam that is pulsed onto the veins in order to seal them off, causing them to dissolve. These light-based treatments require adequate heating of the veins. These treatments can result in the destruction of sweat glands, and the risk increases with the number of treatments.

Basal-cell carcinoma is a common skin cancer and occurs mainly in fair-skinned patients with a family history of this cancer. Sunlight is a factor in about two-thirds of these cancers; therefore, doctors recommend sunscreens with at least SPF 30. One-third occur in non-sun-exposed areas; thus, the pathogenesis is more complex than UV exposure as "the" cause.

The use of a chemotherapeutic agent such as 5-Fluorouracil or imiquimod, can prevent development of skin cancer. It is usually recommended to individuals with extensive sun damage, history of multiple skin cancers, or rudimentary forms of cancer (i.e., solar keratosis). It is often repeated every 2 to 3 years to further decrease the risk of skin cancer.

The following methods are employed in the treatment of basal-cell carcinoma (BCC):

Goldman states that "numerous inherited or congenital conditions display cutaneous telangiectasia".

These include:

- Naevus flammeus (port-wine stain)

- Klippel-Trenaunay syndrome

- Maffucci's syndrome (multiple enchondromas & hemangiomas)

- Hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu syndrome)

- Ataxia-telangiectasia

- Sturge-Weber syndrome, a nevus formation in the skin supplied by the trigeminal nerve and associated with facial port-wine stains, glaucoma, meningeal angiomas and mental retardation

- Hypotrichosis–lymphedema–telangiectasia syndrome, caused by mutation in transcription factor "SOX18"

Diet and lifestyle are believed to play a large role in whether colorectal polyps form. Studies show there to be a protective link between consumption of cooked green vegetables, brown rice, legumes, and dried fruit and decreased incidence of colorectal polyps.

Colorectal polyps can be detected using a faecal occult blood test, flexible sigmoidoscopy, colonoscopy, virtual colonoscopy, digital rectal examination, barium enema or a pill camera.

Malignant potential is associated with

- degree of dysplasia

- Type of polyp (e.g. villous adenoma):

- Tubular Adenoma: 5% risk of cancer

- Tubulovillous adenoma: 20% risk of cancer

- Villous adenoma: 40% risk of cancer

- Size of polyp:

- <1 cm =<1% risk of cancer

- 1 cm=10% risk of cancer

- 2 cm=15% risk of cancer

Normally an adenoma which is greater than 0.5 cm is treated