Acrodermatitis continua of Hallopeau and generalised pustular psoriasis: Should they be the same or different entities?

Pustular psoriasis is characterised by eruptions of neutrophilic sterile pustules. The European Rare and Severe Psoriasis Expert Network consensus defines pustular psoriasis into three subtypes; generalised pustular psoriasis (GPP), palmoplantar pustulosis and acrodermatitis continua of Hallopeau (ACH). Mixed forms are categorised according to their predominant features. However, the Japanese Dermatological Association includes ACH under the diagnosis of GPP. This article aims to review the similarities and differences between ACH and GPP. Based on our review, interleukin (IL)-36RN mutations, the most frequent genetic findings in pustular psoriasis are found most commonly in GPP, followed by ACH. Genotypes of IL-36RN mutations among GPP patients and ACH patients are different between European and Asian ethnicities. IL-36 signalling pathway is the main mechanism. Metabolic diseases are common comorbidities and joint involvement can occur in 20.5%-36.4% of both conditions. Associated plaque psoriasis is more common in GPP than in ACH. Generally, ACH, even the generalised type, does not have systemic inflammation whereas GPP can occur with or without systemic inflammation. ACH can occur before, simultaneously, or after the development of GPP. However, response to treatment for GPP and ACH even in the same patients appear to be different. ACH seemed to be more recalcitrant to treatment than GPP but severe flare of GPP can lead to morbidity and mortality. Although GPP and ACH share genotypes and pathogenesis, we believe that ACH should be classified separately from GPP, and not under diagnosis of GPP. Future research is warranted to satisfactorily distinguish the two conditions.

Case Report: Autochthonous Disseminated Cutaneous, Mucocutaneous, and Visceral Leishmaniasis Caused by Leishmania martiniquensis in a Patient with HIV/AIDS from Northern Thailand and Literature Review.

Autochthonous leishmaniasis cases have been increasing continuously in Thailand over the years. We report multiple presentations of leishmaniasis in a 47-year-old patient with HIV/AIDS from Chiang Rai Province, northern Thailand. Physical examination showed multiple ulcerated papules, nodules, and plaques in a sporotrichoid distribution. Firm mucosal nodules on the hard palate and nasal opening, hepatosplenomegaly, and bilateral inguinal lymphadenopathy were found. Histopathological examination of the biopsies revealed an inflammatory infiltrate containing intramacrophage amastigotes compatible with Leishmania infection. In addition, Leishmania promastigotes were isolated successfully from the palatal biopsy and assigned the code MHOM/TH/2022/CULE6. Using internal transcribed spacer 1 polymerase chain reaction and sequence analysis, the causative parasite was identified as Leishmania martiniquensis. A definitive diagnosis of multiform leishmaniasis with disseminated cutaneous, mucocutaneous, and visceral involvement was established. The patient was administered intravenous amphotericin B 1 mg/kg/d for 2 weeks, followed by oral itraconazole 400 mg daily. At the 2-month follow-up, the cutaneous and mucosal lesions had improved significantly. To our knowledge, this is the first report of mucocutaneous involvement caused by L. martiniquensis in an immunocompromised patient with HIV/AIDS. In addition, we provide a literature review of leishmaniasis cases, reported formally in Thailand, resulting from this autochthonous parasite.