The histopathological spectrum of acute generalized exanthematous pustulosis (AGEP) and its differentiation from generalized pustular psoriasis

Background: Acute generalized exanthematous pustulosis (AGEP) represents a severe, acute, pustular skin reaction that is most often induced by drugs. AGEP can be difficult to differentiate from generalized pustular psoriasis (GPP) both clinically and histopathologically. We present a systematic description of the histopathological spectrum of AGEP and GPP with a focus on discriminating features. Materials and methods: A retrospective, descriptive, comparative histopathological study was completed utilizing step sections of 43 biopsies of 29 cases with a validated diagnosis of probable or definite AGEP and 24 biopsies of 19 cases with an established diagnosis of GPP. Results: In AGEP, biopsies from erythema and pustules showed minor differences, whereas histopathology of the acute stage of GPP showed major differences compared to the chronic stage. Comparing AGEP and GPP, the presence of eosinophils, necrotic keratinocytes, a mixed interstitial and mid-dermal perivascular infiltrate and absence of tortuous or dilated blood vessels were in favor of AGEP. Moreover, chronic GPP was characterized by prominent epidermal psoriatic changes. The frequency of a psoriatic background of AGEP patients in our study was higher than that of psoriasis in the general population. However, histopathology of a subgroup of AGEP patients with a personal history of psoriasis revealed no significant differences from the other AGEP patients. Conclusions: The spectrum of histopathological features of both AGEP and GPP is presented. Despite considerable overlap, subtle consistent histopathological differences and the grade of severity of specific features can help in differentiation. We could neither substantiate earlier reports that follicular pustules exclude AGEP nor did we see vasculitis as a specific feature in AGEP. Our study also supports the concept that AGEP is a separate entity that is distinct from GPP. Kardaun SH, Kuiper H, Fidler V, Jonkman MF. The histopathological spectrum of acute generalized exanthematous pustulosis (AGEP) and its differentiation from generalized pustular psoriasis

Severe osteoarticular involvement in isotretinoin-triggered acne fulminans: two cases successfully treated with anakinra.

Acne fulminans (AF) is a severe form of inflammatory and ulcerated acne associated with fever, malaise, joint swellings and polyarthralgia.1 Osteoarticular lesions are often described and can be radiologically indistinguishable from those observed in synovitis, acne, pustulosis, hyperostosis and osteitis (SAPHO) syndrome.2,3 SAPHO is an autoinflammatory disease characterized by osteoarticular and cutaneous manifestations, the latter including nodular and fulminans acne, hidradenitis suppurativa and palmoplantar pustulosis.3 Thus, AF is considered part of the SAPHO spectrum.

Acute generalized exanthematous pustulosis due to an iodinated contrast radiodiagnostic agent.

peer reviewedIodinated contrast agents are frequently involved in delayed polymorphic adverse skin reactions. Acute generalized exanthematous pustulosis following administration of iodinated contrast agents is a rare but severe form of such reactions. The disease is characterized by the sudden occurrence of an erosive and pustular erythroderma with fever, leukocytosis and sometimes peripheral adenopathies and liver involvement. This condition is considered as an immunologic reaction, primarily involving T lymphocytes. The overall mortality reaches about 1%. Elucidating the differential diagnosis with other acute paroxysmal drug eruptions (toxic epidermal necrolysis, Steven-Johnson syndrome and drug hypersensitivity syndrome) is of paramount importance for establishing the adequate treatment of PEAG

Tinea capitis due to Trichophyton tonsurans in a Maltese patient

We report a case of tinea capitis caused by Trichophyton tonsurans in a 16-year-old male. This appears to be the first documented case of tinea capitis caused by this dermatophyte in a native Maltese patient.peer-reviewe

Severe Infliximab-Induced Alopecia and Scalp Psoriasis in a Woman with Crohn’s Disease: Dramatic Improvement after Drug Discontinuation and Treatment with Adjuvant Systemic and Topical Therapies

Scalp psoriasis with alopecia is a rare cutaneous reaction to tumor necrosis factor alpha antagonists. This reaction often reverses with discontinuation of the offending drug and initiation of topical treatments; however, irreversible hair loss may occur if a scarring alopecia develops. We describe a woman with Crohn’s disease who developed scalp psoriasis and alopecia secondary to infliximab. She had a remarkable recovery after discontinuation of infliximab and treatment with oral minocycline and topical therapy: mineral oil under occlusion, betamethasone lotion, and sequential coal tar, salicylic acid, and ketoconazole shampoos each day. The patient’s alopecia completely resolved within 4 months of initiating this treatment regimen. In summary, early diagnosis of alopecia secondary to tumor necrosis factor alpha antagonist therapy is crucial in preventing diffuse alopecia and scalp psoriasis. In addition to discontinuing the offending agent, initiating aggressive adjuvant treatment with an oral antibiotic, topical therapies, or both, should be considered to reverse tumor necrosis factor alpha antagonist-induced alopecia and/or scalp psoriasis