Crusted scabies is a rare manifestation of scabies characterized by uncontrolled proliferation of mites in the skin. In immunocompromised patients, this infestation is characterized by crusted lesions. The occurrence of the disease in human immunodeficiency virus-infected patients and the widespread use of immunosuppressive agents has led to a renewed interest in the disease. Early recognition and treatment is necessary to avoid an outbreak of scabies. This review highlights the pathogenesis, predisposing factors, clinical features and treatment of crusted scabies.

Dermatitis cruris pustulosa et atrophicans (DCPA) is a distinctive type of chronic superficial folliculitis, primarily affecting the lower limbs. It is characterized by symmetrical follicular pustules of both legs, with cutaneous edema, resulting in alopecia, atrophy and scarring. It was first described by Clarke, from West Nigeria, in 1952 and well illustrated in his book "Skin diseases in the African," under the initial label of "Nigerian shin disease." Subsequently, it was described in India as well, in 1964, and continues to be a problem in dermatology clinics across the country. It is predominantly a disease of men and has a high prevalence in some geographical regions; up to 3-4% in Madras, South India. Some unique features that distinguish DCPA from banal pustular folliculitis include its peculiar localization to the legs, extreme chronicity, resistance to therapy and inevitable alopecia and atrophy of the involved skin, with little postinflammatory hyper- or hypopigmentation. Further, even in the presence of extensive lesions, there are no systemic features. Coagulase-positive Staphylococcus aureus is known to have a role in the etiology of DCPA, but the exact etiopathogenesis still needs to be elucidated. Immunological postulates such as hypergammaglobulinemia have been put forward to explain the chronicity of the condition. A number of therapeutic agents have been tried in various studies, including cotrimoxazole, psoralen with ultraviolet A (PUVA) therapy, ciprofloxacin, pentoxifylline, rifampicin, dapsone, minocycline and mupirocin (topical) with variable success rates. Although a well-recognized entity in dermatology clinics in tropical countries, DCPA has received little attention in the dermatological literature and has only a few studies to its credit. Its unique clinical picture, unclear etiopathogenesis and resistance to therapy afford a vast scope for further investigation and study.

Background: Cutaneous vasculitis presents as a mosaic of clinical and histological findings. Its pathogenic mechanisms and clinical manifestations are varied. Aims: To study the epidemiological spectrum of cutaneous vasculitides as seen in a dermatologic clinic and to determine the clinico-pathological correlation. Methods: A cohort study was conducted on 50 consecutive patients clinically diagnosed as cutaneous vasculitis in the dermatology outdoor; irrespective of age, sex and duration of the disease. Based on the clinical presentation, vasculitis was classified according to modified Gilliam's classification. All patients were subjected to a baseline workup consisting of complete hemogram, serum-creatinine levels, serum-urea, liver function tests, chest X-ray, urine (routine and microscopic) examination besides antistreptolysin O titer, Mantoux test, cryoglobulin levels, antineutrophilic cytoplasmic antibodies and hepatitis B and C. Histopathological examination was done in all patients while immunofluorescence was done in 23 patients. Results: Out of a total of 50 patients diagnosed clinically as cutaneous vasculitis, 41 were classified as leukocytoclastic vasculitis, 2 as Heinoch−Schonlein purpura, 2 as urticarial vasculitis and one each as nodular vasculitis, polyarteritis nodosa and pityriasis lichenoid et varioliforme acuta. Approximately 50% of the patients had a significant drug history, 10% were attributed to infection and 10% had positive collagen workup without any overt manifestations, while 2% each had Wegener granulomatosis and cryoglobulinemia. No cause was found in 26% cases. Histopathology showed features of vasculitis in 42 patients. Only 23 patients could undergo direct immunofluorescence (DIF), out of which 17 (73.9%) were positive for vasculitis. Conclusions: Leukocytoclastic vasculitis was the commonest type of vaculitis presenting to the dermatology outpatient department. The workup of patients with cutaneous vasculitis includes detailed history, clinical examination and investigations to rule out multisystem involvement followed by skin biopsy and DIF at appropriate stage of evolution of lesions. Follow up of these patients is very essential as cutaneous manifestations may be the forme fruste of serious systemic involvement.

Background: There have been controversial reports about the possible association between mycosis fungoides (MF), its leukemic variant Sιzary syndrome (SS) and human T lymphotropic virus type 1 (HTLV-1) in different geographical regions. Aims: The purpose of this study was to explore any association between MF and presence of HTLV-1 infection in Iran. Methods: In a case-control setting, 150 clinically and histopathologically proven MF patients had been admitted to the tertiary referral skin center during a 10-year period and another 150 normal volunteers had been compared with each other for the presence of HTLV-1 infection. Enzyme-linked immunosorbent assay (ELISA) was used to detect antibodies against HTLV-1, and positive results were confirmed with western blotting. Results: Only three MF patients had HTLV-1 infection, whereas two cases of normal subjects had the infection ( P > 0.05). The only three seropositive MF patients were male and from North-Eastern Iran . Conclusion: This study showed that MF does not correlate with HTLV-1 infection in Iran.

Background: Keloids are vexatious swelling on the skin or the conjuctiva. The effects and impacts of these lesions have not been assessed in a keloid endemic environment like Nigeria. Aims: The purpose of this study is to assess the psychosocial impact as well as effects of keloids on the subjects in a black African population where lesions are commonly seen. Methods: This is a prospective study which assesses the impacts of keloid on keloid patients. Consented patients who presented to the Plastic Surgery Clinic of the Lautech Teaching Hospital, Osogbo, Nigeria were recruited into the study. A set of questionnaires were administered to all consented patients. The administered questionnaires were analyzed using SPSS version 10. Results: One hundred and thirty one patients were involved in this study. They comprised of 61 males and 70 females. Most (96.8%) of them had the keloid lesion for more than one year. Sixteen (12.2%) of the patients felt that keloids negatively affect their works, 64 (48.9%) of the patients felt stigmatized by keloids, 28 (56.0%) of them who had lesions in conspicuous parts while 24 (46.2%) had lesions in non-conspicuous parts. Females (59.1%) felt stigmatized than males. Only 47 (35.8%) of the patients believed that keloid swelling limit their social interaction. Conclusion: Keloids do not appear to have significant negative impacts on keloid patients in a keloid-endemic community like a black African population.

Background: Pemphigus disorders are a group of serious and potentially life-threatening diseases affecting skin and/or mucus membranes. Dexamethasone−cyclophosphamide pulse (DCP) therapy has shown promising results in the management of these diseases. Aims: The objective of the study was to assess the outcome of DCP therapy in pemphigus. Methods: Pemphigus patients who had been treated with DCP therapy from 2001 to 2008 were prospectively and retrospectively analyzed. Results: A total of 65 pemphigus patients were enrolled. Male to female ratio was 1 : 1.82. Mean age of patients was 44.65 ± 11.85 years with a range of 14 to 73 years. Thirty two patients completed phase I, of which 28 (9 in phase II, 7 in phase III and 12 in phase III) were maintaining remission and four patients relapsed. Relapse was observed only in patients who discontinued or took irregular treatment. Six patients were declared cured of disease. Five patients died during phase I. Dexamethasone−cyclophosphamide pulse therapy is not absolutely free from adverse effects. Most of the immediate side effects were expected, tolerable and did not pose any problem in continuing treatment. There was a slight increased incidence of weight gain, hypertension, diabetes mellitus, cataract and Cushingoid habitus, since most of our patients also received additional daily oral steroids. Also, there was a high incidence of secondary pyogenic infections of skin lesions and oral candidiasis during phase I. Staphylococcus aureus was the commonest bacteria isolated from the pus of skin lesions. Most of the alterations in laboratory parameters were transitory or correctable, and did not pose a problem in continuing therapy. Conclusions: DCP therapy was found to be effective in inducing and maintaining remission in pemphigus, provided the patients receive regular and complete treatment.

Background: Pityriasis versicolor (PV) is a mild but recurrent superficial fungal infection of stratum corneum. Many predisposing factors such as late teen and young adulthood age, tropical and subtropical climate (and to a lesser extent temperate climate), immunosuppression, malnutrition, use of oral contraceptives, hyperhidrosis, poor hygiene and a few other factors have been proposed for this condition. Aim: Regarding these probable and possible risk factors, we felt that jail is a unique population which can be affected by this infection and therefore we decided to evaluate some aspects of this infection in this population. Methods: In this cross-sectional study in male prisoners of Bandarabbas city, 230 prisoners were randomly selected. One hundred and five (45.67%) of them were diagnosed to be infected. They were also evaluated regarding age, duration of being imprisoned, skin color, site of lesion and its pigmentation change and any concomitant clinical manifestation such as pruritis, burning or cebure. Chi-square test or Fisher's exact test was used for data analysis. Results: Mean age of infected population was 31.62 ± 8.67 years while peak incidence of PV was in 28-32 years age group. The most common color change was hypopigmentation. No case of PV hyperpigmentation was seen. We could not also observe any association between skin color and duration of being imprisoned with the frequency of infection. Conclusion: There seems to be no difference between pattern of infection in the general population and prisoners' population in the aspects evaluated.

Background: Tracking of various parameters associated with laser hair removal is tedious and time consuming. The currently available mathematical models are not simple enough for physicians to be used as a treatment optimization and patient education tool. Aim: The aim of the study was to develop a mathematical model for laser hair removal using agent-based modeling and to make a user-friendly simulation environment. Methods: The model was created using NetLogo. The hairs were modeled as agents oscillating between anagen and telogen. The variables were assigned based on published data whenever possible and the various paths the agent could take were coded as conditional statements. The improvement was assessed using an arbitrary index which takes into account the mean diameter and pigmentation along with the number and length of hairs visible above the surface. Few of the commonly encountered scenarios were simulated using the model. Results: The model is made freely available online (http://www.gulfdoctor.net/model/lhr.htm). Limited number of simulations performed indicated that an eight-week gap between laser sessions may be more effective than a four-week gap. Conclusions: The simulation provides a reliable tool for treatment optimization and patient education as obtaining relevant clinical data is slow and labor-intensive. Its visual interface and online availability makes it useful for everyday use.

Secondary mucin deposition in the skin is a common feature of lupus erythematosus and dermatomyositis. In scleroderma, it occurs uncommonly or in small amount. We describe a 7-year-old boy with progressive, linear, bound-down plaques involving the thighs, lower abdomen and back with no systemic involvement. Histopathology showed features of scleroderma with abundant mucin deposition in the reticular dermis. This report highlights excessive mucin deposition in lesions of morphea.

Kaposi's sarcoma (KS) is a multifocal neoplastic proliferation of endothelial cells predominantly involving skin and other organs. HIV-associated Kaposi's sarcoma has been rarely reported from India. A 38-year-old male presented with persistent swelling on the left lower limb for one year along with multiple erythematous to dusky papules and plaques of one and half months duration and swelling and black discoloration of right lower limb for one month. Cutaneous examination revealed numerous skin colored and erythematous papules and plaques distributed on the left lower limb on the anteromedial aspect and verrucous plaque on the left sole. Multiple erythematous, grouped papules were present over the soft palate. Skin biopsy showed numerous slit like spaces dissecting into the collagen of the upper and mid-dermis along with 'promontory sign' suggestive of Kaposi's sarcoma. Patient was found to be HIV-positive by ELISA test.

Primary systemic amyloidosis is a rare disease. We report three cases of primary systemic amyloidosis, one case with multiple myeloma and two cases without any hematological abnormality. Purpuric lesions were the only presenting symptoms of the patient with multiple myeloma and only on investigation, myeloma was detected. Bone marrow biopsy and serum and urine electrophoresis were normal in remaining two cases. These two patients presented with typical waxy lesions on face. Cutis verticis gyrata was present in one case and carpal tunnel syndrome was seen in other case as an additional diagnostic clue. Macroglossia was present in all three cases. Diagnosis was confirmed in all three cases by biopsy using haematoxylin and eosin staining and Congo red staining. Polarized microscopy was not done because of unavailability.

Dowling Degos disease is a rare condition inherited as autosomal dominant trait characterized by numerous, asymptomatic, symmetrical, progressive, small, round-pigmented macules over axillae and groins, face, neck, arms and trunk, scattered comedo-like lesions (dark dot follicles) and pitted acneiform scars. Histopathology is diagnostic. We are hereby reporting three cases of Dowling Degos disease belonging to two families. Our first and second case belonged to the same family, whereas our third case belonged to different family. In our series, all the patients had onset after puberty. All three cases had reticulate pigmentation over face and/or flexures, black comedones and follicular pits. On histopathological examination of the skin biopsy taken from the lesion over the back, all these patients showed classical histopathological features of Dowling Degos disease. We feel that one should investigate the patient presenting with reticulate pigmentation over the face and flexures with blackish comedone-like lesions, because histopathological features of this condition are unmistakable.