WHITE PIEDRA

A 39-year-old Thai man had eczema on the left groin accompanied by asymptomatic white nodules on the public hair for two weeks. Examination with the Wood's lamp, microscopic examination, culture and biochemical testing showed organisms compatible with Trichosporon beigelii. The diagnosis of "White Piedra" was made, and this is the first case of White Piedra to be reported in Thailand.     

Treatment of multiple lesions of Bowen's disease and squamous cell carcinoma with topical imiquimod

We observed complete clinical and histopathologic remission of papules, plaques and nodules in two patients with multiple lesions of Bowen's disease and squamous cell carcinoma. Our findings indicate that topical imiquimod is a potentially promising therapeutic approach for the local treatment of early forms of cutaneous neoplasia, such as Bowen's disease and squamous cell carcinoma because it is a non-invasive therapy with a good cosmetic outcome. It may therefore be worthy of consideration in a subgroup of patients who cannot have or do not wish to have surgery.     

KERATODERMA HEREDITARIA MUTILANS. ETRETINATE TREATMENT AND ELECTRON MICROSCOPE STUDIES

Keratoderma hereditaria mutilans is a rare inherited cornification disorder characterized by hyperkeratosis of palms and soles with a characteristic "honey-comb" appearance, keratotic constriction furrows of one or more digits (pseudo-ainhum) and threatening spontaneous amputation. Approximately 30 cases have been reported, but the ultrastructural features have not been well characterized. In this article, we describe the clinical, histologic, and ultrastructural findings in our patient. A biopsy specimen taken before treatment with etretinate showed hyperkeratosis with a well-preserved granular layer and acanthosis. Ultrastructural examination disclosed that the spinous cells and granular cells contained marked swollen mitochondria, many desmosomes, and that corneocytes contained many membrane coating granules (MCG) and lipid like vacuoles. After initiation of treatment, considerable clinical improvement was observed, but without significant histologic modification. The principal post-treatment ultrastructural changes were the reduction of mitochondrial swelling in spinous and granular cells and the reduction in the number of MCG in corneocytes. The intercellular spaces showed increased amounts of fine and coarse granular substances. Stimulation of Langerhans cells was observed. Marginal band formation occurred normally after treatment.     

Qualitative and quantitative studies of Paget cells in the horny layer

One case of extramammary Paget's disease was studied by ultrastructural and morphometrical methods to clarify whether or not Paget cells change qualitatively or quantitatively in passing through the epidermis. Paget cells in living layers were observed as large cells with abundant clear cytoplasm, large nuclei, and prominent nucleoli. The cytoplasm was enriched with well developed rough-surfaced endoplasmic reticulum, mitochondria, free ribosomes, and glycogen particles. In contrast, filamentous structures were not developed. Paget cells are connected to each other and adjacent keratinocytes by small desmosomes. In contrast, in the horny layer, Paget cells contained shrunken, flattened nuclei. Cell organelles had degenerated and large lipid droplets were present in the cytoplasm. As disruption of the desmosomes took place, intercellular spaces between Paget cells and keratinocytes widened. Based on the morphometrical analysis by a sonic digitizer computer system, there were statistically significant decreases in areas and diameters of Paget cells between the horny layer and the living cell layers, including the basal, spinous and granular layers. In conclusion, it is suggested that Paget cells change qualitatively and quantitatively after they move into the horny layer from the living layers.     

Ethnic differences in stratum corneum functions between Chinese and Thai infants residing in Bangkok,Thailand

Background/Objectives

Ethnic and racial differences in infant skin have not been well characterized. The purpose of this study was to establish whether there are ethnic differences and similarities in the stratum corneum (SC) functions of Thai and Chinese infants.

Methods

Healthy infants 6 to 24 months of age (N = 60; 30 Thai, 30 Chinese) who resided in Bangkok, Thailand, were enrolled. Transepidermal water loss (TEWL) and SC hydration (capacitance) on the thigh, buttock, and upper arm were measured. Ceramide content was determined in the SC on the upper arm.

Results

SC hydration was not remarkably different between the two ethnicities at any site measured, but TEWL was significantly higher in Chinese infants than in Thai infants at all sites. Hydration of the SC was not significantly correlated with age in either ethnicity. TEWL had significant but weak correlations with age on the thigh and upper arm in Thai infants. Ceramide content was significantly higher in Chinese SC than in Thai SC. No relationship between ceramide content and TEWL or hydration was observed in either ethnicity.

Conclusion

The significant differences in TEWL and ceramide contents between Chinese and Thai infant skin could prove useful in designing skin care and diapering products that are best suited for each ethnicity.     

INFANTILE ACROPUSTULOSIS

Infantile acropustulosis (IA) is a well-recognised syndrome described primarily among black male infants, which may also occur among white and East Asian children. The eruption occurs mainly on the distal areas of the extremities and is characterised by recurrent crops of 1 to 2 mm pruritic papules and pustules in infants from 2 to 10 months of age. We report one patient with infantile acropustulosis and a history of atopic dermatitis and abnormally high IgE serum value. Immunofluorescent studies of involved skin gave negative results. Infantile acropustulosis has been reported by several authors within recent years. The clinical and histological features and differential diagnosis of infantile acropustulosis are discussed. This disease is uncommon but not rare, and persists for about two years.     

Localized periorbital edema induced by Ibuprofen

We documented localized periorbital edema in one patient with ibuprofen sensitivity without underlying chronic urticaria. The reaction developed one hour after ingestion of 200 mg of ibuprofen. No systemic symptoms were observed. No other NSAIDs did not induce symptoms. This patient was able to tolerate doses of ibuprofen after pretreatment with terfenadine. These observations suggest that histamine played a central role in this ibuprofen-induced skin reaction. Treatment with terfenadine enabled the patient to tolerate ibuprofen without experiencing any side effects. To the best of our knowledge, this is the first reported case of periorbital edema induced by ibuprofen.     

Immunohistochemical localization of cathepsin L and cystatin A in normal skin and skin tumors

Cathepsin L, a cysteine proteinase, and cystatin A, an inhibitor of cysteine proteinases, are thought to regulate the invasion and metastasis of malignant cells. In this study, the expression of cathepsin L and cystatin A in skin tumors was investigated immunohistochemically in order to examine the relationship between these two enzymes in the pathophysiology of malignant cells. Formalin-fixed and paraffin embedded specimens from normal skin, seborrheic keratoses, and squamous cell carcinomas were reacted with polyclonal antibodies against rat cathepsin L or cystatin a which cross-react to human cathepsin L and cystatin A, respectively. The consequent immunostaining of these enzymes was observed to be strong in normal skin (4 cases) and seborrheic keratosis (6 cases). In well-differentiated squamous cell carcinoma (SCC) (9 cases), staining for cathepsin L and cystatin A was moderately positive in differentiated tumor cells and negative in undifferentiated SCC (5 cases). The degree of staining of these enzymes was inversely correlated with the differentiation of the malignant cells. These results suggest that the immunohistochemical analysis of cathepsin L and cystatin A is a useful indicator for an aspect of malignancy in human epidermal keratinocytes.