Dermatology

Question 1

Charasterictics of dermatitis herpetiformis

Answer 1

pruritic papular rash, usually present on buttocks and posterior thigh, features of coeliac disease may be present. Anti-tissue transglutaminase (TTG) would need to be done to rule out same.

Question 2

Lichen planus

Answer 2

papular rash in the flexural surface of both wrists. Red or violet papules are seen with white streaks known as Wickham’s striae.

Question 3

Treatment of leprosy

Answer 3

dapsone, clofazimine, rifampicin

Question 4

Measles

Answer 4

maculopapular rash starting behind the ears extending to thecae then upper body downwards. Kopek’s spots are seen

Question 5

Feature of BCC

Answer 5

shiny or pearly pinkish papua with defined telangiectasia with central depression or rolled edges and a central scab

Question 6

Clinical presentation of keratocanthoma?

Answer 6

rapidly enlarging red nodule with a central keratin plug

Question 7

Prognostic features of melanoma

Answer 7

Tumor thickness: The thickness of the primary tumor is the most important prognostic factor for melanoma survival. Thicker tumors are more likely to spread and recur after treatment.
Ulceration: Ulceration occurs when melanoma grows through the epidermis, causing an open wound. Ulcerated tumors have a worse prognosis than non-ulcerated tumors.
Tumor location: The location of the primary tumor is important, with head and neck lesions having a poorer prognosis than extremity lesions.
Nodal disease: For stage III melanomas, the extent of nodal disease is a prognostic factor. The more lymph nodes that contain cancer, the poorer the prognosis.
Metastatic lesions: For stage IV melanomas, the number of metastatic lesions and their site are prognostic factors. Visceral lesions have a poor outcome.
Mitotic rate: Mitotic rate measures how fast cancer cells are dividing. A higher mitotic rate is linked with a poor prognosis.
Age: Older people are at higher risk of developing melanoma.
Gender: Female gender is an independent favorable prognostic factor.
Tumor-infiltrating lymphocytes (TILs): TILs are a key indicator of the host immune response to melanoma

Question 8

Pityriasis
lichenoides (PL)

Answer 8

Pityriasis
lichenoides (PL) is an uncommon cutaneous rash of uncertain aetiology. The acute form, pityriasis lichenoides et varioliformis acuta (PLEVA), and the chronic form, pityriasis lichenoides chronica (PLC), sit at either end of a disease spectrum with many patients showing overlapping features.

The cause of PL is unknown. The main hypotheses are that it may be:
A hypersensitivity reaction to an infection
, such as:
Viruses (Epstein-Barr Virus, cytomegalovirus, human immunodeficiency virus)
Bacteria (Staphylococcus, Streptococcus)
Parasites (Toxoplasma gondii).
An inflammatory reaction to medication, such as anti-TNF agents, statins, antidepressants, vaccines, and radiocontrast dye.
A low-grade lymphoproliferative disorder.
What are the clinical features of pityriasis lichenoides?
PLEVA presents abruptly with a rapidly progressive rash:
10-50 reddish brown, erythematous, ovoid papules, 5-15mm in diameter
Mainly on the trunk and proximal extremities
Evolution into vesicles, pustules, haemorrhagic crusts, and ulcers
Pruritus or burning sensation
Most cutaneous lesions heal with transient or persistent hyper- or hypo-pigmentation.
Constitutional symptoms are usually mild (see complications below).
PLC presents more slowly over several days with:
Larger numbers of small erythematous papules with a brown hue visible on diascopy
Mica-like scale on more established lesions
Lesions at various stages of evolution
Patients often experience periods of relapse and exacerbation.
Patients often show features of both PLEVA and PLC, and PLEVA may evolve into PLC. Mucosal lesions have been reported.