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At least 19 recordsLinked to original sources
PubMed1978

Parakeratosis in some epidermal tumors: fine structural and immunohistochemical similarity between parakeratosis and "Hornmark" -like structure.

Both parakeratosis and "Hornmark" -like structure are basic histopathologic changes found in a variety of skin lesions. In order to investigate more closely the architecture and components of these two structures, three cases of epidermal tumor which showed both parakeratosis and "Hornmark" -like structure were studied by using routine histology and histochemistry, immunofluorescence technique, and electron microscopy. In the intercellular space of the stratum corneum in these two structures, diastase-resistant PAS-positive substance was found. This substance also showed positive immunofluorescence for immunoglobulins, complement, and fibrinogen. Electron microscopically, this substance was moderately electron-dense and fine granular, and was located in the intercellular space and in part in the cytoplasm of the horny cells. On the basis of these findings, this substance was judged more likely to be derived from the components of plasma protein than a result of the degeneration of epidermal cells. Only quantitative difference was observed between these two structure. This substance was considered to play an important role on the increased cohesiveness of the horny cells. However, whether this is a product of antigen-antibody reactions, or the result of the process similar to blood coagulation, remains to be elucidated.

Aged↗
PubMed2003

Granular parakeratosis: a case report and literature review.

BACKGROUND: Granular parakeratosis is suspected to result from an error in epidermal differentiation, leading to variably pruritic, hyperpigmented-to-erythematous patches and plaques. Characteristic histopathologic features include a thickened stratum corneum, compact parakeratosis with retention of keratohyalin granules, vascular proliferation, and ectasia. The pathogenesis of this entity is uncertain. METHODS: We present a case of axillary granular parakeratosis and review the literature. RESULTS: The lesion showed a thickened stratum corneum with compact parakeratosis, slight epidermal hyperplasia, and a sparse perivascular lymphohistiocytic infiltrate. Keratohyalin granules were diffusely present within the parakeratotic stratum corneum, and the retained granular layer showed focal vacuolization. CONCLUSIONS: Granular parakeratosis is a rare form of parakeratosis most often seen in the axilla, although other intertriginous areas may be affected. Unique histopathologic findings allow for a specific diagnosis to be made. Although an irritant contact reaction appears causative, mechanical irritation may also play a role in inducing these skin changes.

Administration, Topical↗
PubMed1995

Cutaneous T-cell lymphoma arising from parakeratosis variegata: long-term observation with monitoring of T-cell receptor gene rearrangements.

BACKGROUND: Parakeratosis variegata is a rare skin disease first described in 1890. Even today, the disease entity remains confusing because various names indicating similar skin conditions have been used. Several cases of parakeratosis variegata have been reported to develop into cutaneous T-cell lymphoma, but there have been no reports describing the occurrence of lymphoma after a long-term follow-up period nor have T-cell receptor gene rearrangements been monitored in this disease. OBJECTIVE: Our purpose was to determine whether parakeratosis variegata (long-standing premycotic condition) can develop into cutaneous T-cell lymphoma. METHODS: We analyzed skin specimens from a patient with a 33-year history of parakeratosis variegata by Southern blotting using a T-cell receptor gene probe. RESULTS: We could detect apparent rearranged bands of T-cell receptor gene in the skin specimens taken in 1993 in contrast to the DNA analysis in 1988 which featured no such rearranged band. CONCLUSION: This case represents a critical stage of parakeratosis variegata converting to lymphoma. Our results indicate that parakeratosis variegata generated monoclonality of T cells in its chronic course.

Adolescent↗
PubMed1997

The transformation of pityriasis lichenoides chronica into parakeratosis variegata in an 11-year-old girl.

Parakeratosis variegata is a rare disorder with unknown aetiology. In a few cases it arises from benign skin diseases such as pityriasis lichenoides et varioliformis acuta (Mucha Habermann disease) or pityriasis lichenoides chronica. However, transformation into malignant diseases such as cutaneous T-cell lymphoma has been observed. We report an 11-year-old girl with a 10-year history of pityriasis lichenoides chronica now presenting with parakeratosis variegata. Analysis of skin infiltrating T cells showed clonally rearranged T-cell receptor gamma chains occurring with a frequency of more than 2%. This finding is compatible with the clinical observation of parakeratosis variegata transforming into a malignant T-cell disorder. We therefore suggest that patients suffering from parakeratosis variegata and other diseases such as pityriasis lichenoides et varioliformis acuta or pityriasis lichenoides chronica should be continuously monitored.

Child↗
PubMed2002

Occurrence of patchy parakeratosis in normal-appearing skin in patients with active atopic dermatitis and in patients with healed atopic dermatitis: a cause of impaired barrier function of the atopic skin.

It remains unclear whether an impaired barrier function often seen in areas of normal-appearing skin in patients with active atopic dermatitis (AD) is primary event in nature or secondary to subclinical eczematous change. We then attempted to evaluate the barrier function of normal-appearing skin in both active and healed AD patients, and as well as see whether a subclinical eczematous change exists or not in the normal-appearing skin using a non-invasive method. Transepidermal water loss (TEWL) measurement and exfoliative cytology method for corneal layer were applied in 153 AD patients who have active skin lesions and 29 individuals with completely healed AD for at least 5 years and 40 normal individuals. The TEWL of normal-appearing skin in severe, moderate and mild AD cases was 10.5+/-2.9, 8.3+/-2.4 and 7.3+/-2.1 g/m2 per h, respectively. The TEWL values in severe and moderate cases were significantly higher than the normal controls (6.2+/-1.6 g/m2 per h). However, the TEWL was not deranged in patients with completely healed AD. An exfoliative cytology examination of corneal layer disclosed that patchy parakeratosis appeared in normal-appearing skin in severe, moderate and mild AD cases at a rate of 42, 29 and 19%, respectively. However, no patchy parakeratosis was recognized in patients with completely healed AD. The occurrence of patchy parakeratosis in normal-appearing skin in patients with active AD suggests that an impaired barrier function often seen in normal-appearing skin in AD patients is secondary to subclinical eczematous change in the area.

Adolescent↗
PubMed2003

Hereditary nasal parakeratosis in Labrador retrievers: 11 new cases and a retrospective study on the presence of accumulations of serum ('serum lakes') in the epidermis of parakeratotic dermatoses and inflamed nasal plana of dogs.

We report 11 new cases of hereditary nasal parakeratosis in Labrador retrievers. The disease was first observed when the dogs were 6 months to 2 years of age, and affected dogs of either sex and all coat colours. Hyperkeratosis and depigmentation were confined to the nasal planum, and affected dogs were otherwise healthy. The principal histological findings in biopsy specimens were marked diffuse parakeratotic hyperkeratosis, multiple intracorneal serum lakes and superficial interstitial-to-interface lymphoplasmacytic dermatitis. Topical applications of propylene glycol in water or white petrolatum were often effective for treatment of the dermatosis. However, continued applications were required to maintain a beneficial response. A retrospective histological study of parakeratotic inflammatory diseases of canine haired skin and inflammatory diseases of the canine nasal planum was performed. The degree of parakeratotic hyperkeratosis and the number and size of intracorneal serum lakes were evaluated. The degree of parakeratotic hyperkeratosis was greater in hereditary nasal parakeratosis specimens than that seen in discoid lupus erythematosus and Malassezia dermatitis. There were more serum lakes in hereditary nasal parakeratosis specimens than in specimens from dogs with discoid lupus erythematosus, Malassezia dermatitis, primary seborrheic dermatitis or zinc-responsive dermatosis. Significant differences in sizes of serum lakes (if present) were not seen.

Animals↗
PubMedDate not supplied

Granular parakeratosis in children: case report and review of the literature.

Granular parakeratosis is a cutaneous eruption with erythematous and/or brownish hyperkeratotic papules and plaques which are exclusively localized to intertriginous areas and show histopathologic features of an unusual form of parakeratosis. The etiology is unknown, but the excessive use of various topical preparations (e.g., ointments and deodorants) has been associated with this disease. It has heretofore been reported only in adults. We report two children, ages 3 and 5 months, with characteristic lesions in the groin associated with topical pomades used to prevent diaper rash. This is the first report associating the clinical presentation and the histopathologic diagnosis of granular parakeratosis in children. The literature on this entity is also reviewed and all case reports are summarized.

Biopsy, Needle↗
PubMed2002

Granular parakeratosis: resolution with topical tretinoin.

Granular parakeratosis is an unusual acquired dermatosis characterized by intertriginous keratotic papules. Histologic examination shows parakeratosis with large numbers of basophilic keratohyaline granules within the stratum corneum. We report a case of a granular parakeratosis of the axilla that cleared rapidly with topical administration of tretinoin.

Administration, Topical↗
PubMed1980

The rate of formation of corneocyte layers after stripping the noninvolved psoriatic skin and its relation to parakeratosis and epidermal enzyme levels.

Corneocyte layer formation rate using dansyl chloride as corneocyte marker was followed in noninvolved skin during a period of 2 weeks after that the skin had been subjected to cellophane stripping. The rate increased after stripping in 7 of 9 tested but it was not paralleled by any apparent parakeratosis. In 1 of 9 patients a Koebner reaction occurred. The corneocyte formation rate in the Koebner reaction was 6.1 times that of the noninvolved skin and with a degree of parakeratosis of 41%. In involved skin, a positive correlation, coefficient 0.81, was shown between corneocyte layer formation rate (range 3.9-15.2 layers/day) and degree of parakeratosis (range 24-100%). In the skin 5 to 14 days after stripping the rate of formation of the corneocyte layer varied from 1.6 to 8.2. In the noninvolved and involved skin the mean rate was 2.2 and 9.7, respectively. In the stripped skin epidermal glucose-6-phosphate dehydrogenase and pyruvate kinase activities generally were the same as those of the noninvolved skin. In the Koebner reacting epidermis the 2 enzymes were increased 2.2 and 1.1 times the noninvolved levels but were statistically not significantly increased from control values.

Adult↗
PubMed1984

The diagnostic value of parakeratosis.

A study of dermatopathological specimens exhibiting parakeratosis has been made and the parakeratosis classified on morphological and topographical criteria. Twelve patterns of parakeratosis have been identified and their association with particular pathological conditions described.

Humans↗
PubMed1989

The significance of a negative Papanicolaou smear with hyperkeratosis or parakeratosis.

The significance of a cytologic diagnosis of hyperkeratosis or parakeratosis on a Papanicolaou smear reported as negative is unknown. We conducted a review of 170 women without uterine descensus who presented to Tripler Army Medical Center cervical clinic with a negative Papanicolaou smear but with hyperkeratosis or parakeratosis noted on the slide. All patients underwent colposcopy, and 64% had either cervical punch biopsy or endocervical curettage. Six women (3.5%) had cervical intraepithelial neoplasia documented histopathologically. We conclude that the cellular findings of hyperkeratosis or parakeratosis on a Papanicolaou smear are not associated with an increased histologic or colposcopic detection of cervical intraepithelial neoplasia.

Adolescent↗
PubMed1982

Corneocyte morphology and formation rate in lichen planus and experimental parakeratosis in subjects with and without psoriasis.

In a recent paper changes in corneocyte morphology and formation rate in psoriasis have been established. In the present study the specificity of these alternations were analysed in two situations. Early lichen planus papules were chosen as a model of hyperproliferation with hypergranulosis and orthohyperkeratosis. Hyperproliferation with parakeratosis was induced by nonanoic acid (CH3(CH2)7COOH) as an experimental model in psoriatics and non-psoriatics. In lichen planus papules, the rate of corneocyte layer formation was 2.4 times that of the non-involved skin. In psoriasis, a similar rate was found in parts with hypergranulosis. A 13% decrease in corneocyte diameter took place in lichen planus lesions--similar to that found in psoriasis. The corneocytes in lichen planus were also thicker than normal cells, though their volumes were similar. Thickness decreased in more superficial locations of these corneocytes. Swelling was a finding during the histological procedure, Corneocytes in the lesion increased markedly in volume, due to swelling. The parakeratosis elicited by nonanoic acid showed cells with irregular membranes and nuclei with non-flattened and irregular borders. The rate of corneocyte layer formation was 2.6 times that of the normal skin. The epidermal reaction to the superficial damage by nonanoic acid did not differ between psoriatics and non-psoriatics. This type of parakeratosis was distinctly different from that present in psoriasis.

Adult↗
PubMed1982

[Clinico-biochemical studies in swine parakeratosis].

Studied were 63 pigs, aged 2-4 months (28-40 kg) with a typical picture of parakeratosis. The investigations followed up some hematological and biochemical indices and the level of macro- and microelements--Ca, P, Zn, Fe, Cu, and Co. In order to elucidate the etiopathogenesis of parakeratosis parallel radioimmunologic studies were carried out with some indices that characterized the functional status of the thyroid gland. In the clinical course of the disease there appeared first nodules that later on changed into dark-red crusts. In a further stage cornification of the epithelial cells set in. Besides, pigs that were affected with parakeratosis had a brighter periphery of the iris (at leats 1/3 of it was affected). The study of the initial diet of such pigs revealed that the Ca:Zn ratio in it was 495:1, which, after correction came to 122:1. With the diseased pigs the plasma level of Zn dropped to 7.49 gamma/cm3, and that of iron--to 14.8 gamma/cm3. Treatment with ZnSO4 at the rate of 0.5 g per head raised these levels up to 17.6 gamma/cm3 and 19.3 gamma/cm3. Such treatment, however, led to the decrease of Cu and Co. Their levels dropped from 0.11 and 0.63 gamma/cm3 to 0.0042 and 0.40 gamma/cm3, respectively.

Animal Feed↗
PubMed1990

Clinical significance of hyperkeratosis and parakeratosis in otherwise negative Papanicolaou smears.

To ascertain the clinical significance of hyperkeratosis and parakeratosis in otherwise negative Papanicolaou smears, we retrospectively reviewed 96 patients with these findings seen during a 32-month period. Evaluation included repeating the smear and performing colposcopy in all patients. Colposcopically directed biopsy and endocervical curettage were performed when appropriate. Only one patient had human papillomavirus (HPV) infection. The isolated finding of hyperkeratosis or parakeratosis was not associated with an increased incidence of cervical intraepithelial neoplasia or HPV and, clinically, was not associated with uterine descensus or vaginal prolapse.

Adult↗
PubMed1991

Axillary granular parakeratosis.

The term axillary granular parakeratosis is proposed for a unique axillary eruption with distinct histopathologic features. Four middle-aged to elderly patients (three women, one man) had unilateral or bilateral, usually pruritic, hyperpigmented to bright red patches in the axillae. Biopsy specimens revealed severe compact parakeratosis with the stratum corneum measuring 80 to 250 microns in maximal thickness, maintenance of the stratum granulosum, remarkable retention of keratohyaline granules throughout the stratum corneum, and vascular proliferation and ectasia. A contact reaction to an antiperspirant/deodorant is suspected as the cause. We speculate that the offending agent alters the maturation sequence of the stratum granulosum and stratum corneum, possibly by interfering with the degradation of filaggrin precursor to filaggrin units.

Aged↗
PubMed1995

Axillary granular parakeratosis.

We report two cases of axillary granular parakeratosis, which is a unique eruption involving the axilla that has distinctive histopathologic features. Both of our patients had slightly pruritic, hyperpigmented patches in the axilla. The biopsy specimens revealed severe compact parakeratosis with maintenance of the stratum granulosum and retention of keratohyalin granules throughout the stratum corneum, which was markedly thickened and measured between 90 to 185 microns. The exact etiology is not known, but this conditions is believed to represent a contact reaction to an antiperspirant or deodorant.

Aged↗
PubMed2002

Granular parakeratosis: four paediatric cases.

Axillary granular parakeratosis (GP) was first described in 1991 as a peculiar eruption presenting with erythematous hyperpigmented and hyperkeratotic papules and plaques of the cutaneous folds frequently associated with pruritus. Histopathology shows a characteristic picture with a conspicuous granular appearance of the parakeratotic horny layer. Until now, only 24 adults, mainly women aged over 40 years, have been reported with GP. We demonstrate that this condition can also occur in young children. Four children aged between 10 and 24 months had asymptomatic hyperpigmented scaling papules 2-3 mm in diameter located on the groin, lower back, buttocks and flanks. In all cases the mothers reported the habit of frequent washing followed by application of many topical products. Biopsy revealed the same features in all four patients: the epidermis showed a thickened horny layer with a unique compact parakeratosis with maintenance of the stratum granulosum and marked retention of keratohyaline granules throughout the stratum corneum.

Diaper Rash↗