Monilethrix--improvement by hormonal influences?

Keratosis Pilaris and its Subtypes: Associations, New Molecular and Pharmacologic Etiologies, and Therapeutic Options

Keratosis pilaris is a common skin disorder comprising less common variants and rare subtypes, including keratosis pilaris rubra, erythromelanosis follicularis faciei et colli, and the spectrum of keratosis pilaris atrophicans. Data, and critical analysis of existing data, are lacking, so the etiologies, pathogeneses, disease associations, and treatments of these clinical entities are poorly understood. The present article aims to fill this knowledge gap by reviewing literature in the PubMed, EMBASE, and CINAHL databases and providing a comprehensive, analytical summary of the clinical characteristics and pathophysiology of keratosis pilaris and its subtypes through the lens of disease associations, genetics, and pharmacologic etiologies. Histopathologic, genomic, and epidemiologic evidence points to keratosis pilaris as a primary disorder of the pilosebaceous unit as a result of inherited mutations or acquired disruptions in various biomolecular pathways. Recent data highlight aberrant Ras signaling as an important contributor to the pathophysiology of keratosis pilaris and its subtypes. We also evaluate data on treatments for keratosis pilaris and its subtypes, including topical, systemic, and energy-based therapies. The effectiveness of various types of lasers in treating keratosis pilaris and its subtypes deserves wider recognition.

Genetics of syndromic and non-syndromic hereditary nail disorders

The nail is a unique epithelial skin appendage made up of a fully keratinized nail plate. The nail can be affected in several systemic illnesses, dermatological diseases, and inherited nail disorders. Nail dystrophies can present as isolated disorders or as a part of syndromes. Substantial progress has been achieved in the management and diagnosis of nail diseases; however, not much is known about the underlying molecular controls of nail growth. The homeostasis and development of the nail appendage depend on the intricate interactions between the epidermis and underlying mesenchyme, and comprise different signaling pathways such as the WNT signaling pathway. Digit-tip regeneration in mice and humans has been a known fact for the past six decades; however, only recently the underlying biological mechanisms by which the nail organ achieves digit regeneration have been elucidated. Moreover, significant progress has been made in identifying nail stem cells and localizing stem cell niches in the nail unit. More fascinating, however, is the role they play in orchestrating the processes that lead to the regeneration of the digit. Further elucidating the role of nail stem cells and the signaling pathways driving epithelial-mesenchymal interactions in the nail unit might contribute to the development of novel therapeutic tools for amputees.

Koilonychia: an update on pathophysiology, differential diagnosis and clinical relevance

Koilonychia, a concave nail dystrophy, has multiple aetiologies and may be hereditary, acquired or idiopathic. Within dermatology, koilonychia is often a manifestation of an inflammatory dermatosis such as psoriasis or lichen planus, or a sign of onychomycosis. Other disease associations include iron store abnormalities, Plummer-Vinson Syndrome, nutritional deficiencies and occupational or traumatic aetiologies. In young children, koilonychia of the toenails is commonly transient and idiopathic, although familial and syndromic cases are reported. The dermatologist must be aware of the potential cutaneous and systemic associations with koilonychia in order to guide appropriate workup, treatment and/or referral. An algorithm for evaluation of koilonychia is presented along with discussion of common causes of koilonychia and a comprehensive list of all known associations.

Trichodystrophies: A hair-raising differential diagnosis

The appearance of an individual's hair is said to be reflective of internal health. Patients with hair shaft disorders commonly present with fragile, lusterless, sparse hair in addition to psychosocial distress. Hair shaft disorders may be hereditary or acquired and may present in children or adults. Due to the varied presentations, the differential diagnosis for hair is broad and often confusing. The authors present a question-by-question guide to help clinicians arrive at the correct diagnosis.

Acquired nonscarring diffuse hair loss in a 3-year-old girl

A 3-year-old girl showed fine, sparse, and brittle scalp hair without signs of cicatricial cutaneous alterations. Dermoscopy as well as scanning electron microscopy revealed elliptical nodes as well as constricted regions along the hair shaft.

Monilethrix: improvement with acitretin

Monilethrix is a rare hereditary disorder that affects the hair and is characterized by shaft anomaly. There is no known treatment that successfully cures the condition. In this report we present a case of monilethrix in a 7-year-old girl treated with oral acitretin. A very good clinical and cosmetic result was obtained while treatment was continued. However, clinical symptoms recurred after discontinuation of acitretin therapy.

Severe monilethrix associated with intractable scalp pruritus, posterior subcapsular cataract, brachiocephaly, and distinct facial features: a new variant of monilethrix syndrome?

Monilethrix is a rare developmental hair shaft defect characterized by small elliptical node-like deformities with increased hair fragility resulting in partial or diffuse alopecia. The disorder is usually transmitted in an autosomal dominant fashion with incomplete penetrance and variable expressivity, but autosomal recessive inheritance has also been reported. It is thought to be without systemic involvement, whereas keratosis pilaris and follicular papules are almost invariably associated features. We describe an instance of monilethrix in a 9-year-old boy from consanguineous parents, characterized by universal dystrophic alopecia associated with intractable scalp pruritus, diffuse keratosis pilaris, and bilateral posterior subcapsular cataracts. His disease was further characterized by physical underdevelopment and distinct features of hypertelorism, a wide-based nose, long philtrum, relatively large mouth with thick lower lip, enlarged forehead, small, receding chin, short neck, and rounded (ultrabrachycranial) skull. The findings in our patient suggest that "monilethrix syndrome" is an appropriate term for defining the instances of monilethrix associated with other abnormalities. We conclude that our patient may represent a new and severe, autosomal recessive variant of monilethrix syndrome.

Keratosis pilaris and hereditary koilonychia without monilethrix

Keratosis pilaris is found commonly in isolation as well as associated with other conditions. We describe a family with keratosis pilaris and hereditary koilonychia, with an autosomal dominant pattern of inheritance. These two findings have only been previously found in the context of monilethrix. The coexistence of the two disorders suggests a close association of their genetic pathogenesis.

Downregulation of the potential suppressor gene IGFBP-rP1 in human breast cancer is associated with inactivation of the retinoblastoma protein, cyclin E overexpression and increased proliferation in estrogen receptor negative tumors

The complex insulin-like growth factor network of ligands, receptors and binding proteins has been shown to be disturbed in breast cancer. In addition to defects in proteins controlling cell cycle checkpoints, this type of aberrations could affect tumor growth and survival thereby influencing both tumor aggressiveness and potential response to treatments. We have previously identified the T1A12/mac25 protein, which is identical to the IGFBP-rP1, as a differentially expressed gene product in breast cancer cells compared with normal cells. Here we compare the expression of IGFBP-rP1 in 106 tumor samples with known status of cell cycle aberrations and other clinicopathological data. This was done using a tumor tissue section array system that allows for simultaneous immunohistochemical staining of all samples in parallel. Cytoplasmic staining of variable intensity was observed in most tumors, 15% lacked IGFBP-rP1 staining completely, 20% had weak staining, 32% intermediate and 33% showed strong staining. Low IGFBP-rP1 was associated with high cyclin E protein content, retinoblastoma protein (pRb) inactivation, low bcl-2 protein, poorly differentiated tumors and higher stage. There was a significantly impaired prognosis for patients with low IGFBP-rP1 protein tumors. Interestingly, IGFBP-rP1 showed an inverse association with proliferation (Ki-67%) in estrogen receptor negative tumors as well as in cyclin E high tumors suggesting a separate cell cycle regulatory function for IGFBP-rP1 independent of interaction with the estrogen receptor or the pRb pathway.