Differential diagnosis includes Angelman syndrome, Mowat–Wilson syndrome and Rett syndrome.

Diagnosis can be made at birth by identifying the symptoms of the child. Ultrastructural diagnosis where tissues are analyzed is using electron microscopy is also conducted. A specimen of skin is obtained via a skin biopsy and analyzed to see any tell tale characteristics.Genetic testing can also be done to identify the mutation on the FATP4 gene associated with fatty acid synthesis. Genetic consultation through a genetic counsellor is done to determine whether the individual has this syndrome and reduces the chances of misdiagnoses with other cutaneous diseases.

Diagnosis is made by showing a mutation in the TCF4 gene.

Around 50% of those affected show abnormalities on brain imaging. These include hypoplastic corpus callosum with a missing rostrum and posterior part of the splenium with bulbous caudate nuclei bulging towards the frontal horns.

Electroencephalograms show an excess of slow components.

All have low levels of immunoglobulin M (IgM) but features of an immunodeficiency are absent.

The diagnosis of rhizomelic chondrodysplasia punctate can be based on genetic testing, as well as radiography results, plus an examination(physical) of the individual.

There are no life-threatening complications after the perinatal period (around the time of birth) and the skin conditions persist but to a lesser degree of severity. Individuals have a favourable prognosis as symptoms can be managed and past the infancy stage are not life-threatening. The red skin edema improves after a three-week period but the ichthyosis scaling persists. Asthma has been recorded in some cases later on in the individual's life and sign of atopic dermatitis persist, follicular hyperkeratosis and small amounts of scaling at the scalp that goes on into adulthood but otherwise the individual continues a healthy life.

Painful red swelling of the hands and feet in a patient receiving chemotherapy is usually enough to make the diagnosis. The problem can also arise in patients after bone marrow transplants, as the clinical and histologic features of PPE can be similar to cutaneous manifestations of acute (first 3 weeks) graft-versus-host disease. It is important to differentiate PPE, which is benign, from the more dangerous graft-versus-host disease. As time progresses, patients with graft-versus-host disease progress to have other body parts affected, while PPE is limited to hands and feet. Serial biopsies every 3 to 5 days can also be helpful in differentiating the two disorders (Crider et al., 1986).

Diagnosis is mainly based on clinical features. However, biopsy has been useful in diagnosis as well as in differentiating between the different types of the disease.

The cooling of hands and feet during chemotherapy may help prevent PPE (Baack and Burgdorf, 1991; Zimmerman et al., 1995). Support for this and a variety of other approaches to treat or prevent acral erythema comes from small clinical studies, although none has been proven in a randomised controlled clinical trial of sufficient size.

The diagnosis of an individual with acrodermatitis enteropathica includes each of the following:

- Plasma zinc level (lab)

- Light microscopy (skin biopsy)

- Electron microscopy (histology)

Management of rhizomelic chondrodysplasia punctate can include physical therapy, additionally orthopedic procedures improved function sometimes in affected people. However the prognosis is poor in this condition.

The differential diagnosis is quite extensive and includes

- Buschke–Fischer–Brauer disease

- Curth–Macklin ichthyosis

- Gamborg Nielsen syndrome

- Greither disease

- Haber syndrome

- Hereditary punctate palmoplantar keratoderma

- Jadassohn–Lewandowsky syndrome

- Keratosis follicularis spinulosa decalvans

- Keratosis linearis with ichthyosis congenital and sclerosing keratoderma syndrome

- Meleda disease

- Mucosa hyperkeratosis syndrome

- Naegeli–Franceschetti–Jadassohn syndrome

- Naxos disease

- Olmsted syndrome

- Palmoplantar keratoderma and leukokeratosis anogenitalis

- Pandysautonomia

- Papillomatosis of Gougerot and Carteaud

- Papillon–Lefèvre syndrome

- Punctate porokeratotic keratoderma

- Richner–Hanhart syndrome

- Schöpf–Schulz–Passarge syndrome

- Unna Thost disease

- Vohwinkel syndrome

- Wong's dermatomyositis

Bart–Pumphrey syndrome (also known as "Palmoplantar keratoderma with knuckle pads and leukonychia and deafness") is a cutaneous condition characterized by hyperkeratoses (knuckle pads) over the metacarpophalangeal, proximal and distal interphalangeal joints.

It was characterized in 1967.

It can be associated with GJB2.

Usually, a common form of treatment for the condition is a type of hand cream which moisturises the hard skin. However, currently the condition is incurable.

Treatment is symptomatic and may include nonsteroidal anti-inflammatory drugs (NSAIDs) and corticosteroids to reduce swelling, antibiotics and immunosuppressants. Surgery may be indicated to relieve pressure on the facial nerves and reduce swelling, but its efficacy is uncertain. Massage and electrical stimulation may also be prescribed.

Howel–Evans syndrome is an extremely rare condition involving thickening of the skin in the palms of the hands and the soles of the feet (hyperkeratosis). This familial disease is associated with a high lifetime risk of esophageal cancer. For this reason, it is sometimes known as tylosis with oesophageal cancer (TOC).

The condition is inherited in an autosomal dominant manner, and it has been linked to a mutation in the "RHBDF2" gene. It was first described in 1958.

Acrodermatitis enteropathica without treatment is fatal, and affected individuals may die within a few years. There is no cure for the condition. Treatment includes lifelong dietary zinc supplementation.

In addition to genetic tests involving the sequencing of "PEX" genes, biochemical tests have proven highly effective for the diagnosis of Zellweger syndrome and other peroxisomal disorders. Typically, Zellweger syndrome patients show elevated very long chain fatty acids in their blood plasma. Cultured primarily skin fibroblasts obtained from patients show elevated very long chain fatty acids, impaired very long chain fatty acid beta-oxidation, phytanic acid alpha-oxidation, pristanic acid alpha-oxidation, and plasmalogen biosynthesis.

Currently, no cure for Zellweger syndrome is known, nor is a course of treatment made standard. Infections should be guarded against to prevent such complications as pneumonia and respiratory distress. Other treatment is symptomatic and supportive. Patients usually do not survive beyond one year of age.

MDM is most common on the Dalmatian island of Mljet (or "Meleda"), thought to be because of a founder effect. It is of autosomal recessive inheritance. It may be caused by a mutation on the "SLURP1" gene, located on chromosome 8.

Oudtshoorn is a town in Western Cape (formerly Cape Province), South Africa, where KWE ("Oudtshoorn skin") was first described. The disorder is quite prevalent among Afrikaners of South Africa, a population which can be defined as caucasoid native-speakers of Afrikaans, with northwestern European lineage. Among this group, KWE occurs at a rate of approximately 1/7,200.

This relatively high rate of occurrence has been attributed to the founder effect, in which a small, often consanguinous population is formed out of the larger ancestral population, resulting in a loss of genetic diversity. In the context of KWE, the founder effect was confirmed by haplotype analysis, which indicates that the chromosomal origin of a possible genetic mutation responsible for the disorder is particularly common among affected Afrikaners. This is also true in other South Africans of European descent with KWE, and the chromosome of interest in both these and Afrikaner patients strongly points to an unspecified ancestor or ancestral group that may have settled around the Oudtshoorn area.

A second lineage known to exhibit KWE has been reported in Germany, although there it is less prevalent and appears to involve the chromosome from a different ancestral origin than that seen in Afrikaners. KWE has also been noted in other countries around the northwestern region of Europe, such as Denmark.

Meleda disease (MDM) or "mal de Meleda", also called Mljet disease, keratosis palmoplantaris and transgradiens of Siemens, (also known as "Acral keratoderma," "Mutilating palmoplantar keratoderma of the Gamborg-Nielsen type," "Palmoplantar ectodermal dysplasia type VIII", and "Palmoplantar keratoderma of the Norrbotten type") is an extremely rare autosomal recessive congenital skin disorder in which dry, thick patches of skin develop on the soles of the hands and feet, a condition known as palmoplantar hyperkeratosis.

This disease is often found during the first two months of an infants life, breast-fed infants with a higher chance. Male and female infants are affected equally.

DPN is not a premalignant condition nor is it associated with any underlying systemic disease. DPN lesions show no tendency to regress spontaneously, and often increase in size and number as an individual ages.

Keratolytic Winter erythema ( Oudtshoorn disease and Oudtshoorn skin, }is a rare autosomal dominant skin disease of unknown cause which causes redness and peeling of the skin on the palms and soles. Onset, increased prominence and severity usually occurs during winter. It is a type of genodermatosis.

The name "Oudtshoorn skin" derives from the town of Oudtshoorn in the Western Cape province of South Africa, where the disorder was first described. It is one of several genetic disorders known to be highly prevalent among the Afrikaner population.

Patients are usually managed by a multidisciplinary team including surgeons, gynecologists, and dermatologists because of the complex nature of this disorder. Follow-up for the increased risk of breast cancer risk includes monthly breast self-examination, annual breast examination, and mammography at age 30 or five years earlier than the youngest age of breast cancer in the family. The magnitude of the risk of breast cancer justifies routine screening with breast MRI as per published guidelines.