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Background: Epidermal keratinization disorders comprise a heterogeneous group of skin diseases that share the common feature of abnormal epidermal maturation, often leading to a disturbed stratum corneum., Objective: To describe two cases of an unusual disorder of epidermal keratinization., Methods: The clinical features of two unrelated patients with a long-standing widespread cutaneous eruption are described. Histopathologic examination and immunohistochemical studies were performed on skin biopsy specimens., Results: The eruption was characterized by symmetric erythematous, flat, discrete papules with a polygonal shape and fine scaling. The papules covered most of the skin surface and, in some areas of the trunk, they were arranged along the lines of cleavage, parallel to the ribs. There was no facial, mucosal, nail, or palmoplantar involvement; the teeth and hair were normal. The first patient had a sister with an identical eruption, and a brother of the second patient was said to have similar skin lesions. Histopathology revealed well-demarcated areas of compact eosinophilic orthokeratotic hyperkeratosis overlying a slightly acanthotic epidermis. Lesional skin showed weaker immunoexpression for connexin 43 compared with normal skin., Limitations: Only two patients and one sibling were investigated., Conclusion: We propose the name "saurian papulosis" to describe this newly described clinicopathologic entity., (Copyright © 2011 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.)

Background: The evolution of squamous cell carcinoma (SCC) on sun-exposed areas is a multistep process triggered by ultraviolet radiation (UVR), in which precursor lesions exist. However, the exact classification of the various lesions in this process, mainly solar keratosis (SK), is still disputed, and its pathogenesis requires further clarification., Objective: To further elucidate the evolution of SCC on sun-damaged skin by correlating the levels of p53 protein expression, a parameter that reflects UVR damage to cells, and the morphology of the lesions that develop on sun-exposed areas., Methods: Biopsy specimens from normal skin (n = 4), normal skin with various degrees of solar elastosis (SE) (n = 16), various degrees of SK (n = 17) and SCCs from sun-exposed (n = 12) and sun-protected (n = 7) areas were stained with anti-p53 antibodies. A semiquantitative evaluation of the degree of staining was performed and correlated with the histological features., Results: Nuclear staining in keratinocytes was observed already in normal skin with mild SE and was increased gradually to its highest level of expression in advanced SK. It was also expressed in SCCs, but to a lesser degree. Statistical analysis revealed association between the morphology of the lesion and the level of p53 expression (P < .01); it also showed that in general the level of p53 is correlated with the histology of the lesion (P < .001). Furthermore, with regard to p53 expression, two groups of lesions exist: one showing a low level of expression of p53 that includes normal skin, skin with various degrees of SE and SCC from sun-protected areas, and a second group showing a high level of expression that includes SK and SCC occurring on sun-damaged skin., Limitation: This is an immunohistochemical study of relatively few cases and in which the antibody detects all types of p53 protein., Conclusions: This study furnishes further evidence that the development of SCC on sun-damaged skin is a gradual process not only morphologically but also on the molecular level. The process starts already in normal-appearing epidermis with SE. In that respect, SK should be regarded as a part of the continuum in the development of SCC, analogous to the situation in other epithelia. The molecular events involved in the development of SCC on sun-exposed areas may be different from those involving the development of SCC on sun-protected areas.

Keratosis lichenoides chronica (KLC) is a rare acquired disease of adulthood, of unknown etiology, characterized by keratotic parallel linear lesions, retiform plaques, and keratotic, often follicular papules, chronicity and lichenoid histopathologic features. KLC of pediatric onset is considered extremely rare. Its features and relationship to adult onset KLC are unknown. We studied 8 cases of pediatric-onset KLC in the literature and 6 personal cases and compared them with 40 reported adult-onset KLC patients. The following features characterize pediatric-onset KLC: familial occurrence; probable autosomal recessive inheritance; early or congenital onset with facial erythemato-purpuric macules; forehead, eyebrow, and eyelash alopecia; pruritus; and a low frequency of other cutaneous and systemic abnormalities. Pediatric-onset KLC may represent a different disease or a subset of adult-onset KLC, with special genetic and clinical characteristics. Determining its precise nosology will have prognostic and therapeutic implications.

We describe a family with woolly hair and ulerythema ophryogenes spanning four generations. Both woolly hair and ulerythema ophryogenes have been associated with Noonan syndrome and cardiofaciocutaneous syndrome (CFC), two disorders with considerable phenotypic overlap. This family did not exhibit any of the other findings characteristic of either Noonan syndrome or CFC, similar to a previously described pedigree with hereditary woolly hair. Woolly hair elicits a broad differential diagnosis, including woolly hair nevus and several genodermatoses. Our report reviews the evaluation of woolly hair and discusses the conditions associated with this physical finding.

Focal palmoplantar and gingival keratosis is a rare autosomal dominant disease whose clinical features, and in particular, pathologic alterations and molecular etiology remain to be well defined. Recently we observed a German family affected by the disease in at least 3 consecutive generations. The 4 patients examined showed circumscribed and painful hyperkeratosis at the weight-bearing plantar skin since infancy, rather mild palmar hyperkeratosis, and continuous leukokeratosis confined to the maxillary and mandibulary attached gingiva. There were no nail changes, subungeal keratoses, or follicular hyperkeratosis. Light and electron microscopy of the plantar and gingival lesions revealed alterations of epidermolytic hyperkeratosis. Mutations in the known keratin genes were excluded by linkage analysis using microsatellite markers. We conclude that focal palmoplantar and gingival keratosis is a clinically distinct palmoplantar ectodermal dysplasia that is pathologically characterized by epidermolytic alterations, but is most probably not caused by a mutation in a keratin gene.

Background: Mutations in tumor suppressor gene p53 are very common in many human cancers. They are present in more than 90% of squamous cell carcinomas (SCCs) and are usually found in actinic keratoses (AKs). Data demonstrate a strong relationship between the early effects of ultraviolet radiation (UVR) on p53 in skin and the development of AK and SCC., Objective: The purpose of this article is to review specific data about the p53 tumor suppressor gene, UVR, and their interaction to cause AKs., Methods: The published, peer-reviewed literature is reviewed and a published proposal for the mechanism for UVR-induced carcinogenesis is explained., Results: The specific effect of UVR on the p53 tumor suppressor gene, including its impact on apoptosis, in humans, and in animals, suggests a cause-effect relationship between UVR and the earliest mutations seen in AKs., Conclusion: AKs result from UVR in a process by which UVR mutates a known tumor suppressor gene (p53). It is likely that the mutated cells expand preferentially in a clonal fashion at the expense of the normal surrounding keratinocytes to develop into a clinical lesion of AK.

Background: Loss of p53 tumor suppressor function is a critical step in the development of diverse malignancies, including skin cancers in nonimmunosuppressed patients where UV-specific p53 gene mutations have been identified. In tumors associated with human papillomavirus (HPV), such as cervical carcinoma, p53 may be inactivated instead by binding to a viral oncoprotein., Objective: Our purpose was to examine the hypothesis that HPV may play an analogous role in the development of posttransplant skin cancer., Methods: p53 Immunoreactivity, suggestive of p53 gene mutation, was examined by immunocytochemistry. Oncogenic HPV DNA was detected by polymerase chain reaction., Results: Comparable p53 immunoreactivity was seen in skin tumors from both transplant and nontransplant patients. HPV DNA was not demonstrated in any tumor specimen., Conclusion: Our data do not implicate oncogenic HPV in posttransplant skin cancer. p53 Gene mutation, rather than HPV-induced p53 degradation, may be more significant in the development of these tumors.

A 7-year-old girl had erythematous hyperkeratotic papules and plaques that improved in summer and recurred in winter since the age of 4 months. She had had irregular, ridge-like erythematosquamous lesions on the arms with the same seasonal variation. The lesions on the arms improved with age. Light and electron microscopic examination showed marked degeneration of keratinocytes and prominent apoptosis. Her older brother had a similar but milder dermatosis. We believe these cases may represent a variant of keratosis lichenoides chronica.

We report a case of multiple minute digitate hyperkeratosis. The patient had hundreds of keratotic lesions--some tiny and spiked, others larger, flat papules--localized on the trunk and arms. Histologic sections showed focal areas of compact hyperorthokeratosis with few dermal changes. Ultrastructurally, keratohyalin granules were smaller than normal. The keratin pattern was one of a normal variant. Odland bodies present. Various family members of the patient, in different generations, were affected.

Three members of a family with numerous ectodermal abnormalities are described. These anomalies primarily include patchy alopecia beginning in childhood, premature cataracts, widespread keratosis pilaris, and psoriasis. The alopecia and premature cataracts appear to follow an autosomal dominant inheritance pattern with incomplete penetrance and appear to be linked. Psoriasis also occurs in several members of this family and probably represents a separate but possibly related genodermatosis. This kindred has features of both keratosis follicularis spinulosa decalvans and ichthyosis follicularis, and the disorder seems to fit into the group of follicular hyperkeratosis disorders.

Many tumors of the skin, whether originating from ectoderm or mesoderm, exist in either single or multiple form. In the multiple state there are frequently associations with other cutaneous and systemic abnormalities, sometimes serious and even life-threatening. The resultant syndrome is almost always inherited in an autosomal dominant pattern. By contrast, solitary lesions are not heritable, nor are they associated with other stigmata. The solitary forms appear in middle or late life, the multiple, syndromic forms in childhood or early adulthood.