Characterization of the inflammatory cell infiltrate in herald patches and fully developed eruptions of pityriasis rosea

BACKGROUND

Pityriasis rosea (PR) is a common cutaneous papulosquamous disorder affecting young adults. Previous studies have suggested possibilities of a viral aetiology and the involvement of cell-mediated immunity, but these remain unproven to date.

AIM

To elucidate the possible pathomechanisms in PR by characterizing the inflammatory cellular infiltrate in herald patches and fully developed PR eruptions.

METHODS

In total, 12 biopsy specimens from 6 patients diagnosed with PR were examined. For each patient, biopsies were taken from both a herald patch and a secondary patch. Specimens were processed for histopathological examination and immunohistochemical staining with a large panel of monoclonal antibodies.

RESULTS

Histopathologically, all specimens showed epidermal changes such as parakeratosis, orthokeratosis, epidermal hyperplasia and spongiosis. Less common results included epidermal exocytosis and focal parakeratosis. In all biopsies, the dermal infiltrate of lymphocytes stained positively for monoclonal antibodies specific for T cells. The ratio of the CD4+ (helper) vs. CD8+ (cytotoxic) T cells in the dermal infiltrate was increased in most specimens. Increased staining for Langerhans cells was seen within the dermis of lesional skin. There were no marked differences found in histopathology and immunohistochemistry between the herald patch and secondary lesions. Overall, there was a lack of natural killer cell and B-cell activities in PR lesions.

CONCLUSIONS

Our results support a predominantly T-cell mediated immunity in the development of PR.

Community-based study of acne vulgaris in adolescents in Singapore

BACKGROUND

There are few studies on the prevalence of acne vulgaris among Asian teenagers.

OBJECTIVES

To determine the epidemiology of acne in teenagers in Singapore.

METHODS

A community-based cross-sectional study in 1045 adolescents aged 13-19 years.

RESULTS

Of these respondents, 88% identified themselves as having acne. Eight hundred and six of these respondents were examined by a dermatologist, and 51.4% were classified as having mild acne, 40% moderate acne and 8.6% severe acne. Isolation of Propionibacterium acnes was attempted in 262 subjects. Cultures were positive in 174 subjects, giving an isolation rate of 66.4%. Antibiotic-resistant strains of P. acnes were detected in 26 isolates (14.9%). Eleven of these 26 subjects (42%) had previously been treated or were presently on antibiotic treatment for acne, but the other 58% of students who had antibiotic-resistant strains of P. acnes did not give a history of prior antibiotic therapy. Teenagers expressed psychological distress over acne, and believed that hormonal factors, diet and hygiene were important factors in causing acne.

CONCLUSIONS

There is a need for accessible, accurate education on acne and its appropriate treatment.

Sweet's syndrome: a spectrum of unusual clinical presentations and associations

BACKGROUND

Sweet's syndrome (SS) is the prototypic neutrophilic dermatosis. First described in 1964, the characterization of new clinical associations, unique histopathological findings and clinical variants have stimulated much interest and discussion recently. However, the prevalence of these unusual variants and clinical associations within a single cohort of patients, has not been described.

OBJECTIVES

To describe and evaluate the prevalence of unusual clinical and histopathological features, as well as the clinical associations of SS seen in patients from the National Skin Centre, Singapore.

METHODS

This is a retrospective study of all consecutive cases of SS seen at our centre over a 5.5-year period (June 1999-December 2004). Data on associated systemic diseases was obtained from the medical records and matched with information from the National Cancer Registry, Singapore. Patients not actively followed up for more than 3 months were contacted for their updated health status.

RESULTS

Thirty-seven patients were identified. Ten (27%) had non-idiopathic SS. These were associated with haematological disorders, connective tissue disorders, infections or a drug. Twenty-nine patients (78%) had at least one atypical clinical or histopathological feature. Atypical clinical features included bullous lesions, SS with hand involvement or neutrophilic dermatoses of the hands and the concomitant existence of subcutaneous SS with pyoderma gangrenosum. SS was the presenting feature in three patients with infections caused by atypical organisms, including Mycobacterium chelonae, Penicillium species and Salmonella type D. Unique histopathological variants included subcutaneous SS and lesions containing an admixture of mature and immature neutrophils. Subcutaneous neutrophilic inflammation seemed to be more common in patients with an underlying haematological disorder. This group of patients also had a lower mean haemoglobin level.

CONCLUSIONS

Unusual clinical and histopathological variants of SS described in the literature are similarly encountered in our cohort of patients, with some features being more common than others. We highlight and discuss some unique clinical and histopathological observations seen in our patients with SS.

Trigeminal trophic syndrome: an unusual cause of a non-healing cheek ulcer

Trigeminal trophic syndrome (TTS) is an uncommon condition characterised by anaesthesia, paraesthesias and ala nasi ulceration, following peripheral or central damage to the trigeminal nerve. Only about 100 cases have been described in the literature to date. We report a 74-year-old woman who presented with a right cheek ulcer accompanied by pruritus and paraesthesia for three months. An old right cerebellar infarct was demonstrated on magnetic resonance imaging of the brain. Vertebrobasilar insufficiency leading to the cerebellar infarct is likely to have predisposed her to developing TTS. An underlying infectious, malignant and vasculitic cause for the ulcer was excluded by a skin biopsy. An increased awareness of the predisposing factors and clinical presentations of this important disfiguring condition is necessary to ensure prompt diagnosis and treatment.

Cyclosporin in the treatment of severe atopic dermatitis: a retrospective study

INTRODUCTION

The aims of this study were to determine the clinical profile of patients with atopic dermatitis who were treated with cyclosporin, and to assess the treatment duration, dose and response to cyclosporin therapy.

MATERIALS AND METHODS

Casenotes of patients with atopic dermatitis treated with cyclosporin from January 2000 to February 2002 were analysed.

RESULTS

There were 15 patients (9 males and 6 females) (age range, 1 to 58 years). All had severe disease. The mean initiating dose of cyclosporin was 2.8 mg/kg/day and the mean maximum dose was 3.3 mg/kg/day. Average duration of treatment was 6 months. Rapid improvement was seen within the first 2 weeks and maximum benefit was attained at a mean of 10 weeks. At the end of treatment, 73 % of patients had improved from severe to none, mild or moderate disease. Five patients had a flare of eczema during therapy, 3 related to decrease in dose of medication. All patients relapsed within 3 months of cessation of cyclosporin. One patient with borderline hypertension developed worsening of blood pressure, which returned to baseline after cessation of cyclosporin and treatment with atenolol. No patient had sustained rises in serum creatinine.

CONCLUSION

Cyclosporin is very useful in patients with severe, recalcitrant atopic dermatitis who have failed conventional therapy. It offers rapid relief of an otherwise disabling skin disease, but its effect is not long-lasting and relapses occur in almost all cases if followed up for long enough.

Comparison of completely versus incompletely excised cutaneous squamous cell carcinomas

INTRODUCTION

This is a retrospective case series of cutaneous squamous cell carcinomas (SCCs) which were incompletely excised in National Skin Centre, Singapore from 1991 to 1995. This study compared the characteristics of completely excised versus incompletely excised cutaneous SCCs.

MATERIALS AND METHODS

All patients with histologically confirmed SCCs were traced from computerised medical database and information regarding patient profile, tumour characteristics, surgical treatment and outcome were collated. All patients were recalled for clinical examination and documentation of cure. Completely excised and incompletely excised SCCs were compared with regards to the patient and tumour characteristics.

RESULTS

There were 57 patients with 63 SCCs who were treated with surgical excision over the 5-year period. Fifty were recalled for physical examination. There were 30 males and 27 females and their mean age was 83.3 years. All except 1 were Chinese of Fitzpatrick skin type 4. One-third of patients had daily or weekly sun exposure in the past and 21.1% had occupational sun exposure; 3.5% had prior arsenic exposure and 3.5% were previously treated with radiotherapy for other malignancies. The mean duration of SCCs was 18.7 months; 7.9% of patients had multiple SCCs and 15.9% had underlying actinic keratoses. The mean diameter of the tumours was 1.97 cm and nearly half were located on the head and neck. All the SCCs were primary and localised to the skin; 84.1% of them were completely excised with a 4 to 6 mm margin. Incompletely excised SCCs were associated with the male sex, larger tumours and tumours on the genitals and lower limbs.

CONCLUSION

In our experience, the tumour clearance rate is 84.1% following conventional excision. Incomplete excision is associated with male sex, larger tumours and those on the genitals and lower limbs.

Lymphomatoid papulosis associated with recurrent cutaneous T-cell lymphoma

INTRODUCTION

Lymphomatoid papulosis is a chronic benign disease which may be associated with malignant lymphomas. This case illustrates the relapsing and remitting nature of both lymphomatoid papulosis and its potential of developing cutaneous T-cell lymphoma and narrow-band ultraviolet B (NB-UVB) phototherapy as a new modality of treatment of early-stage mycosis fungoides in these patients.

CLINICAL PICTURE

A 44-year-old woman has had recurrent crops of papules and nodules of lymphomatoid papulosis on the limbs for 15 years. Histological features are consistent with the type B lesions of lymphomatoid papulosis. Eight years after the initial onset of these lesions she developed cutaneous T-cell lymphoma (mycosis fungoides). Since then, she has had recurrence of mycosis fungoides following the cessation of phototherapy, but had no evidence of systemic involvement.

TREATMENT

The lesions of lymphomatoid papulosis responded to intermittent courses of oral methotrexate. Mycosis fungoides was treated with oral psoralen and ultraviolet A phototherapy with good response. Unfortunately, the lesions relapsed, whenever phototherapy was discontinued. The most recent recurrence of mycosis fungoides was treated with NB-UVB therapy.

OUTCOME

The papules of lymphomatoid papulosis continue to appear but she remains free of lesions of mycosis fungoides, 10 months after cessation of NB-UVB therapy.

CONCLUSION

Long-term surveillance is essential in all cases of lymphomatoid papulosis as accurate predictors for the development of malignant lymphoma in these individuals are still lacking.

Extensive calcinosis cutis in relapsed acute lymphoblastic leukaemia

INTRODUCTION

Hypercalcaemia with calcinosis cutis occurring at relapse of acute lymphoblastic leukaemia (ALL) is rare and unusual.

CLINICAL PICTURE

A 19-year-old lady with B precursor ALL presented with extensive waxy, verrucous, tender plaques over the flexures of her arms and legs a week after relapse of leukaemia. She was found to have hypercalcaemia, hyperphosphataemia, hyperuricaemia and acute renal impairment. Skin biopsy was consistent with calcinosis cutis. There was no evidence of metastatic calcification in other organs.

TREATMENT

Hypercalcaemia was treated with aggressive hydration and intravenous pamidronate. High doses of analgesics were required for partial pain relief.

OUTCOME

Cutaneous lesions proved resistant to early calcium lowering and were a source of constant pain. She succumbed to leukaemia four months later.

CONCLUSION

Treatment of calcinosis cutis was unsatisfactory and would have been dependent on the successful treatment of the underlying leukaemia.