Differentiation of inflammatory papulosquamous skin diseases based on skin biophysical and ultrasonographic properties: A decision tree model.

BACKGROUND: The biophysical and ultrasonographic properties of the skin change in papulosquamous diseases. AIMS: : To identify biophysical and ultrasonographic properties for the differentiation of five main groups of papulosquamous skin diseases. METHODS: Fifteen biophysical and ultrasonographic parameters were measured by multiprobe adapter system and high-frequency ultrasonography in active lesions and normal control skin in patients with chronic eczema, psoriasis, lichen planus, pityriasis rosea and parapsoriasis/mycosis fungoides. Using histological diagnosis as a gold standard, a decision tree analysis was performed based on the mean percentage changes of these parameters [(lesion-control/control) ×100] for differentiation of the diseases. RESULTS: The accuracy of the decision tree model for differentiation of five diseases was 67% which developed based on changes in stratum corneum hydration, epidermal thickness, skin pH, melanin index, R0 (reciprocal of firmness) and erythema. Among the flowcharts for pairs of diseases, three models for differentiation had high accuracy (> 95%): those of psoriasis from lichen planus, pityriasis rosea, and parapsoriasis/mycosis fungoides. LIMITATIONS: Validation studies on a larger sample size in situations where the diagnosis is unclear are needed to confirm the accuracy and applicability of decision trees. CONCLUSION: Skin biophysical and ultrasonographic properties may help in the differentiation of papulosquamous diseases as simple and non-invasive tools.

Profile of skin biopsies and patterns of skin cancer in a tertiary care center of Western Nepal.

BACKGROUND: Skin biopsy is the method to assist clinicians to make definite dermatological diagnosis which further helps in holistic management. Skin cancers are relatively rare clinical diagnosis in developing countries like Nepal, but the prevalence is on rise. OBJECTIVES: To investigate the profile of skin biopsies and frequencies and pattern of skin cancers in a tertiary care centre of Western Nepal. MATERIALS AND METHODS: The materials consisted of 434 biopsies (1.37%) out of 31,450 OPD visits performed in the Department of Dermatology, Manipal Teaching Hospital, Pokhara, Nepal, during the period of Dec 2011-Nov 2014. Data were collected and analyzed using SPSS-16 with reference to incidence, age, sex, race and clinical and histopathological features. RESULTS: The commonest disorders observed in biopsies were papulosquamous lesions, skin tuberculosis of different types, benign skin tumors, leprosy, collagen and fungal diseases. Viral diseases were rarely seen, probably due to straight forward clinical diagnosis. Dermatological malignancies accounted for 55/434 (12.67%) of biopsies. Skin disorders in general were commoner in females 280/434 (64%), including malignancies 32/55(58.2%). Mean age of patients with skin cancer was 54.5 years. Facilities for proper laboratory investigation of dermatological disorders will improve the quality of life. CONCLUSIONS: The most prevalent lesion in skin biopsies was papulosquamous disorders followed by skin tuberculosis of different types. Dermatological malignancy constituted 55/434 (12.67%) cases. The prevalence of skin malignancy is on rise in Nepalese society probably due to increase in life expectancy and better diagnostic services.

Acquired Blaschkoid dermatitis.

Acquired Blaschkoid dermatitis characterised by unilateral relapsing inflammatory disease along the lines of Blaschko. A 40-year-old Indian male presented with unilateral erythematous, itchy grouped papules on the left side of the chest, abdomen, back and left arm of 15 days duration. The eruption stopped abruptly at the midline of the torso, completely sparing the right side of the body. The lesions were arranged in whorls and streaks corresponding to the lines of Blaschko. Skin biopsy showed hyperkeratosis and features suggestive of sub-acute spongiotic dermatitis with lymphocytic infiltrate around the blood vessels in the dermis. Patient was diagnosed as a case of Blaschkoid dermatitis. To the best of our knowledge, this is the first case of this condition being reported from India.