Microscopic analysis of the hair shows twisted hairs of unequal size and different shapes (pili torti, aniso- and poikilotrichosis), longitudinal breaks and breaks located at nodes (trichorrhexis nodosa). Scanning electron microscopy might reveal hair budding (trichorrhexis blastysis). Biochemical analysis may reveal sulfur-deficient brittle hair (trichothiodystrophy; note that disulfide bonds determine hair waviness).

Immunodeficiency is a consistent feature with low serum concentrations of immunoglobulins which may improve with age and a poor immunological response to childhood vaccination. T cell dysfunction and abnormal antibody generation have been reported.

The assessment for Smith-Finemen-Myers syndrome like any other mental retardation includes a detailed family history and physical exam that tests the mentality of the patient. The patient also gets a brain and skeletal imaging though CT scans or x-rays. They also does a chromosome study and certain other genetic biochemical tests to help figure out any other causes for the mental retardation.

The diagnosis of SFMS is based on visible and measurable symptoms. Until 2000, SFMS was not known to be associated with any particular gene. As of 2001, scientists do not yet know if other genes are involved in this rare disease. Generic analysis of the ATRX gene may prove to be helpful in diagnosis of SFMS.

Dyschromatosis symmetrica hereditaria (also known as "reticulate acropigmentation of Dohi", and "symmetrical dyschromatosis of the extremities") is a rare autosomally inherited dermatosis. It is characterized by progressively pigmented and depigmented macules, often mixed in a reticulate pattern, concentrated on the dorsal extremities. It presents primarily in the Japanese, but has also been found to affect individuals from Europe, India and the Caribbean.

Fluorescein angiography is usually performed for diagnosis and follow-up of patients with POHS.

Based on the presence of extraocular findings, such as neurological, auditory and integumentary manifestations, the "revised diagnostic criteria" of 2001 classify the disease as complete (eyes along with both neurological and skin), incomplete (eyes along with either neurological or skin) or probable (eyes without either neurological or skin) . By definition, for research homogeneity purposes, there are two exclusion criteria: previous ocular penetrating trauma or surgery, and other concomitant ocular disease similar to VKH disease.

This disease is caused by mutation in the double stranded RNA specific adenosine deaminase (ADAR1) gene. This gene is located on the long arm of chromosome 1 (1q21).

Treatments are usually based on the individuals symptoms that are displayed. The seizures are controlled with anticonvulsant medication. For the behavior problems, the doctors proscribe to a few medications and behavioral modification routines that involve therapists and other types of therapy. Even if mental retardation is severe, it does not seem to shorten the lifespan of the patient or to get worse with age.

Clinical diagnosis can be made with the naked eye using the ABCD guideline or by using dermatoscopy. An online-screening test is also available to help screen out benign moles.

Reticular pigmented anomaly of the flexures (also known as "dark dot disease", and "Dowling–Degos' disease") is a fibrous anomaly of the flexures or bending parts of the axillae, neck and inframammary/sternal areas. It is an autosomal-dominant pigmentary disorder that may appear in adolescence or adulthood. This condition is due to mutations in structural/desmosomal proteins found within stratified squamous epithelium.

Dark dot disease is associated with "KRT5".

If tested in the prodromal phase, CSF pleocytosis is found in more than 80%, mainly lymphocytes. This pleocytosis resolves in about 8 weeks even if chronic uveitis persists.

Functional tests may include electroretinogram and visual field testing. Diagnostic confirmation and an estimation of disease severity may involve imaging tests such as retinography, fluorescein or indocyanine green angiography, optical coherence tomography and ultrasound. For example, indocyanine green angiography may detect continuing choroidal inflammation in the eyes without clinical symptoms or signs. Ocular MRI may be helpful and auditory symptoms should undergo audiologic testing. Histopathology findings from eye and skin are discussed by Walton.

The diagnosis of VKH is based on the clinical presentation; the diagnostic differential is extensive, and includes (almong others) sympathetic ophthalmia, sarcoidosis, primary intraocular B-cell lymphoma, posterior scleritis, uveal effusion syndrome, tuberculosis, syphilis, and multifocal choroidopathy syndromes.

In season 6 of House MD in the episode 12 titled Remorse, House diagnoses his patient with Wilson's Disease in absence of Kayser-Fleischer rings by removing the nail polish to note the blue nails.

The long-term prognosis for patients with Stargardt disease is widely variable although the majority of people will progress to legal blindness.

Stargardt disease has no impact on general health and life expectancy is normal. Some patients, usually those with the late onset form, can maintain excellent visual acuities for extended periods, and are therefore able to perform tasks such as reading or driving.

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

Macular telangiectasia type 1 must be differentiated from secondary telangiectasis caused by retinal vascular diseases such as retinal venous occlusions, diabetic retinopathy, radiation retinopathy, sickle cell maculopathy, inflammatory retinopathy/Irvine–Gass syndrome, ocular ischemic syndrome/carotid artery obstruction, hypertensive retinopathy, polycythemia vera retinopathy, and localized retinal capillary hemangioma. In addition, Macular telangiectasia type 1 should be clearly differentiated from dilated perifoveal capillaries with evidence of vitreous cellular infiltration secondary to acquired inflammatory disease or tapetoretinal dystrophy. Less commonly, macular telangiectasis has been described in association with fascioscapulohumeral muscular dystrophy, incontinentia pigmenti, and familial exudative vitreoretinopathy with posterior pole involvement.

Macular telangiectasia type 2 is commonly under-diagnosed. The findings may appear very similar to diabetic retinopathy, and many cases ave been incorrectly ascribed to diabetic retinopathy or age-related macular degeneration. Recognition of this condition can save an affected patient from unnecessarily undergoing extensive medical testing and/or treatment. MacTel should be considered in cases of mild paramacular dot and blot hemorrhages and in cases of macular and paramacular RPE hyperplasia where no other cause can be identified.

People with ED often have certain cranial-facial features which can be distinctive: frontal bossing is common, longer or more pronounced chins are frequent, broader noses are also very common. In some types of ED, abnormal development of parts of the eye can result in dryness of the eye, cataracts, and vision defects. Professional eye care can help minimize the effects of ED on vision. Similarly, abnormalities in the development of the ear may cause hearing problems. Respiratory infections can be more common because the normal protective secretions of the mouth and nose are not present. Precautions must be taken to limit infections.

Spitz nevi are uncommon. Their annual incidence was estimated in a coastal population of sub-tropical Queensland to be 1.4 cases per 100,000 people. For comparison, the annual incidence of melanoma in the same population, which is high by world standards is 25.4 cases per 100,000 people.

Although they are most commonly found on people in their first two decades of life, the age range for people with Spitz nevi is from 6 months to 71 years, with a mean age of 22 years and a median age of 19 years.

It often requires a dermatologist to fully evaluate moles. For instance, a small blue or bluish-black spot, often called a blue nevus, is usually benign but often mistaken for melanoma. Conversely, a junctional nevus, which develops at the junction of the dermis and epidermis, is potentially cancerous.

A basic reference chart used for consumers to spot suspicious moles is found in the mnemonic A-B-C-D, used by institutions such as the American Academy of Dermatology and the National Cancer Institute. The letters stand for asymmetry, border, color, and diameter. Sometimes, the letter E (for elevation or evolving) is added. According to the American Academy of Dermatology, if a mole starts changing in size, color, shape or, especially, if the border of a mole develops ragged edges or becomes larger than a pencil eraser, it would be an appropriate time to consult with a physician. Other warning signs include a mole, even if smaller than a pencil eraser, that is different from the others and begins to crust over, bleed, itch, or become inflamed. The changes may indicate developing melanomas. The matter can become clinically complicated because mole removal depends on which types of cancer, if any, come into suspicion.

A recent and novel method of melanoma detection is the "ugly duckling sign" It is simple, easy to teach, and highly effective in detecting melanoma. Simply, correlation of common characteristics of a person's skin lesion is made. Lesions which greatly deviate from the common characteristics are labeled as an "ugly duckling", and further professional exam is required. The "little red riding hood sign", suggests that individuals with fair skin and light colored hair might have difficult-to-diagnose melanomas. Extra care and caution should be rendered when examining such individuals as they might have multiple melanomas and severely dysplastic nevi. A dermatoscope must be used to detect "ugly ducklings", as many melanomas in these individuals resemble non-melanomas or are considered to be "wolves in sheep clothing". These fair skinned individuals often have lightly pigmented or amelanotic melanomas which will not present easy-to-observe color changes and variation in colors. The borders of these amelanotic melanomas are often indistinct, making visual identification without a dermatoscope very difficult.

People with a personal or family history of skin cancer or of dysplastic nevus syndrome (multiple atypical moles) should see a dermatologist at least once a year to be sure they are not developing melanoma.

Blue nails, or more formally azure lunula, are characterized by a blue discoloration of the lunulae, seen in argyria and cases of hepatolenticular degeneration (Wilson's disease), also having been reported in hemoglobin M disease and hereditary acrolabial telangiectases.

In Wilson's disease the blue color involves the lunula (most intense pigmentation) and fades proximally. In argyria, the nail is permanently pigmented a slate-blue color and is most evident in the lunula. Minocycline and Zidovudine can also turn the nail plate blue-gray. There are also reports of hydroxyurea as a rare cause.

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

STGD1 is the most common form of inherited juvenile macular degeneration with a prevalence of approximately 1 in 10,000 births.

Fleischer rings are pigmented rings in the peripheral cornea, resulting from iron deposition in basal epithelial cells, in the form of hemosiderin. They are usually yellowish to dark-brown, and may be complete or broken.

They are named for Bruno Fleischer.

Fleischer rings are indicative of keratoconus, a degenerative corneal condition that causes the cornea to thin and change to a conic shape.

Some confusion exists between Fleischer rings and Kayser-Fleischer rings. Kayser-Fleischer rings are caused by copper deposits, and are indicative of Wilson's disease, whereas Fleischer rings are caused by iron deposits. One example of a medical condition that can present with Fleischer rings is Keratoconus.

Treatment requires careful consideration of angiographic findings when a choroidal neovascular membrane is suspected which is a condition that responds to treatment. A vitreo-retinal specialist (an ophthalmologist specialized in treatment of retinal diseases) should be consulted for proper management of the case.

Presumed ocular histoplasmosis syndrome and age-related macular degeneration (AMD) have been successfully treated with laser, anti-vascular endothelial growth factors and photodynamic therapy. Ophthalmologists are using anti-vascular endothelial growth factors to treat AMD and similar conditions since research indicates that vascular endothelial growth factor (VEGF) is one of the causes for the growth of the abnormal vessels that cause these conditions.

In most instances, the diagnosis of toxoplasmic retinochoroiditis is made clinically on the basis of the appearance of the characteristic lesion on eye examination.

Seropositivity (positive blood test result) for Toxoplasma is very common and therefore not useful in diagnosis; however, a negative result i.e. absence of antibodies is often used to rule out disease. Others believe that serology is useful to confirm active toxoplasmic retinochoroiditis, not only by showing positivity but by also showing a significant elevation of titers: The mean IgG values were 147.7 ± 25.9 IU/ml for patients with active disease versus 18.3 ± 20.8 IU/ml for normal individuals.

Antibodies against Toxoplasma:

- IgG : appear within the first 2 weeks after infection, typically remain detectable for life, albeit at low levels;and may cross the placenta.

- IgM : rise early during the acute phase of the infection, typically remain detectable for less than 1 year, and do not cross the placenta.

- IgA : Measurement of IgA antibody titers may also be useful in a diagnosis of congenital toxoplasmosis in a fetus or newborn because IgM production is often weak during this period and the presence of IgG antibodies may indicate passive transfer of maternal antibodies in utero. IgA antibodies however usually disappear by 7 months.

In atypical cases, ocular fluid testing to detect parasite DNA by polymerase chain reaction or to determine intraocular production of specific antibody may be helpful for establishing etiology.

Neuroimaging is warranted in AIDS patients presenting with these findings because intracranial toxoplasmic lesions have been reported in up to 29% of these patients who have toxoplasmic chorioretinitis.