pemphigoid is also increased in patients with psoriasis and in patients treated with phototherapy. A medication, trauma, or skin infection can trigger the onset of bullous pemphigoid. Medications which are associated with bullous pemphigoid include penicillamine, frusemide, spironolactone, captopril, penicillin and its derivative, sulfasalazine, salicylazosulfapyridine, phenacetin, nalidixic acid, topical fluorouracil, neuroleptics, and dipeptidyl‐peptidase 4 (DPP‐4) inhibitors. Bullous pemphigoid is associated with underlying malignancy and appropriate screening is important.
Schmidt E, Zillikens D. Pemphigoid diseases. The Lancet. 2013;381(9863):320–332.
https://www.ncbi.nlm.nih.gov/pubmed/23237497
2. Answer: C
This patient is likely to have coeliac disease. Classically, patients with coeliac disease present with steatorrhea, weight loss, nutrient deficiency, and resolution of the mucosal lesions (villous atrophy) and symptoms upon withdrawal of gluten‐containing foods. The malabsorption may cause weight loss, severe anaemia, neurologic disorders from deficiencies of B vitamins, and osteopenia from deficiency of vitamin D and calcium. Coeliac disease can exist in a very mild form and go largely undetected.
Dermatitis herpetiformis (DH) is a rare but persistent immunobullous disease associated with coeliac disease. It develops in 15 to 25% of patients with coeliac disease. There is a genetic predisposition with an association with HLA, DQ2, and DQ8. Some patients have a personal or family history of other autoimmune diseases including thyroid disease, pernicious anaemia, type 1 diabetes, vitiligo, and Addison disease.
DH is characterised by its intense pruritus. Because of severe itching, intact vesicles are rarely seen. DH has a symmetrical distribution. The location of the lesions aids in the diagnosis. Lesions are most commonly seen on the extensor surfaces of knees, elbows and on buttocks. Lesions are seldom seen on the face, neck, scalp, palms, or soles.
DH diagnosis is based on typical clinical picture and demonstration of IgA deposition in papillary dermis. DH usually has a good prognosis, with the majority of patients responding well to a strict gluten‐free diet and medication.
Salmi T. Dermatitis herpetiformis. Clinical and Experimental Dermatology. 2019;44(7):728–731.
https://onlinelibrary.wiley.com/doi/full/10.1111/ced.13992
3. Answer: A
This patient has erythema nodosum which is likely secondary to previously undiagnosed Crohn’s disease which can be hypothesised from her history of mouth ulcers, abdominal pain, diarrhoea, and microcytic anaemia. Her serum calcium level is normal and CXR is normal which does not suggest sarcoidosis. There is also no lymphadenopathy or hepatosplenomegaly to suggest lymphoma.
Erythema nodosum is the most common type of panniculitis. Generally, it is idiopathic in 50% of cases, however there are many possible causes (Table 3.1). Erythema nodosum often occurs in association with granulomatous disease including sarcoidosis, tuberculosis, and granulomatous colitis. The hallmark of erythema nodosum is painful, tender, erythematous, subcutaneous nodules that typically are located symmetrically on the anterior surface of the lower extremities and is a nonspecific cutaneous reaction pattern to a variety of antigens.
Table 3.1 Common causes of erythema nodosum.
| Infection |
| Streptococcal pharyngitisMycoplasmaTuberculosisSyphilisViral infection: HSV, EBV, hepatitis B and C, HIV |
| Inflammatory bowel disease |
| Ulcerative colitisCrohn’s disease |
| Sarcoidosis |
| Drugs |
| Antibiotics: sulfonamides, amoxicillin; oral contraceptives |
| Lymphoma and other malignancies |
Evidence supports the involvement of a type IV delayed hypersensitivity response to numerous antigens. Erythema nodosum represents an inflammatory process involving the septa between subcutaneous fat lobules, with an absence of vasculitis and the presence of radial granulomas. These nodules tend to be self‐limiting; they do not ulcerate and usually resolve without atrophy or scarring. Pain can be managed with NSAIDs and prednisolone (1 mg/kg) may be used until the erythema nodosum resolves if underlying infection has been excluded. However most importantly, any underlying causes should be treated.
Chowaniec M, Starba A, Wiland P. Erythema nodosum – review of the literature. Reumatologia/Rheumatology. 2016;2:79–82.
https://www.termedia.pl/Erythema-nodosum-review-of-the-literature,18,27671,1,1.html
4. Answer: A
The combination of palpable purpura, arthritis/arthralgia, abdominal pain. and haematuria in a young person is highly suggestive of Henoch‐Schonlein (HSP) or IgA vasculitis. HSP is an immune‐mediated vasculitis associated with IgA deposition. Skin biopsy shows leukocytoclastic vasculitis with IgA staining of superficial dermal vessels. Some degree of renal involvement is seen in 35 to 54% of adult patients. Renal biopsy primarily shows IgA deposition in the mesangium in both HSP and IgA nephropathy suggesting similar pathogenesis.
The majority of HSP cases are preceded by an upper respiratory tract infection suggesting a potential infectious trigger. Streptococcus, staphylococcus, and parainfluenza are the most commonly implicated pathogens.
Diagnosis of HSP is based on the presence of purpura (palpable) or petechiae (without thrombocytopaenia) with lower limb predominance (mandatory criterion) plus at least one of the following four features: (i) abdominal pain, (ii) arthritis or arthralgia, (iii) leukocytoclastic vasculitis or proliferative glomerulonephritis with predominant deposition of IgA on histology, (iv) renal involvement (haematuria, red blood cell casts, proteinuria). Laboratory tests focus on assessing renal involvement (urinalysis, urine microscopy, proteinuria, serum creatinine).
There are no blood tests specific for HSP. Although the IgA system plays a central role in the pathophysiology, measurement of serum levels of total IgA is not helpful in confirming the diagnosis or providing prognostic information. Galactose‐deficient IgA1 serum levels seem to distinguish patients with HSP nephritis from patients without nephritis.
Gastrointestinal involvement is relatively common with typical colicky abdominal pain. In a recent case series, main clinical manifestations were abdominal pain (100%), nausea and vomiting (14.4%), melaena
