br Acute generalized exanthematous pustulosis AGEP

Acute generalized exanthematous pustulosis (AGEP) is often drug induced and is characterized by the acute onset of nonfollicular sterile pustules on a diffuse erythematous base, fever, and neutrophilia. Roujeau et al proposed some criteria for AGEP based on clinical and pathological findings. Adverse cutaneous reactions to paracetamol (acetaminophen) are rare. These generally involve acute hypersensitivity or fixed drug eruption, occasionally involve eczema or vasculitis, and infrequently involve Stevens–Johnson syndrome or toxic epidermal necrolysis. There are only seven reported cases of paracetamol-induced AGEP, including one case of child. Our case was a 4-year-old girl who presented with fever for 3 days and erythematous pustular eruptions, and had a personal history of asthma, atopic dermatitis, and allergic rhinitis. There was neither a family nor a personal history of psoriasis. She experienced similar episodes since the age of 5 months, presenting with generalized erythematous papules with a neutrophilic infiltration in the epidermis seen on histological examination. Before admission, the patient took unknown medications for 1–2 weeks for cough and rhinorrhea. A generalized blanchable skin rash and pustules developed on the patient\'s face and fingers. She was admitted because of suspicion of acute bronchitis, drug eruption, or atopic dermatitis with secondary bacterial infection. She was prescribed antimicrobials (vancomycin and clindamycin), antihistamines (dexchlorpheniramine, hydroxyzine, and cetirizine), procaterol hydrochloride, and guaifenesin. Amoxicillin and cephalexin were suspected as the culprit SGC707 and were prohibited. Paracetamol was added several times during admission. The patient\'s rash progressed, and the number of pustules increased. There was widespread erythema on her face, trunk, and limbs accompanied by many small, nonfollicular, superficial pustules with desquamations (A, 1B, and 1C). The mucous membranes, palms, and soles were spared. She had a fever of up to 39°C. Laboratory testing revealed neutrophilia (white blood cells 11,300/mm with 72% neutrophils) and an elevated C-reactive protein level at 22.4 g/L. Liver, renal function, and routine urine test results were within the normal limits. Microbiological examinations performed on admission (blood culture, throat swab viral culture, and pustule swabs) yielded negative results for bacterial and viral organisms. Antistreptococcal antibody titers remained low. A diagnosis of AGEP was established using criteria by Roujeau et al. The patient was treated with systemic steroids (methylprednisolone 1 mg/kg/d, tapered gradually during week 1), and the pustules resolved within 1 week, followed by mild desquamation. One month after the skin lesions subsided, patch tests were performed using the cutaneous adverse drug reaction series CAD-1000 (Chemotechnique Diagnostics, Malmo, Sweden) and other prescribed medications () mounted on Finn Chambers on Scanpor tape (Epitest Ltd., Tuusula, Finland). Patch tests were applied for 48 hours and read on Days 2, 3, and 7. The patient had a strong positive reaction to paracetamol (D, 1E, and 1F). Other test results were negative. AGEP is a rare cutaneous adverse drug reaction with an incidence of one to five cases per million persons per year. In Taiwan, approximately 25% of all patients with AGEP were pediatric cases (4 of 16 cases, 3 boys and 1 girl). More than 90% of reported AGEP cases are drug induced, whereas others are related to viral infections or mercury allergy. The incidence of paracetamol-related AGEP is even rarer, accounting for 1.5% (1/63 cases) of all AGEP cases. The pathogenesis of AGEP involves a T cell-related immune reaction. Keratinocytes play an important role in secreting chemokines for neutrophils and eosinophils. Early diagnosis of AGEP in children is a challenge, as it can initially be easily mistaken for other diseases such as staphylococcal scalded skin syndrome, generalized pustular psoriasis, Sneddon–Wilkinson disease, scabies, candidiasis, tinea, and viral exanthems. Therefore, clinicians should be aware of the criteria for AGEP, including the presence of widespread nonfollicular minute sterile pustules on an erythematous base, fever exceeding 38°C, a blood neutrophil count > 7000/mm, and an acute course with spontaneous resolution in <15 days.