Port-wine stains are a type of vascular birthmark caused by the abnormal development of capillaries in the skin. These pinkish-purplish discolorations present at birth and are associated with medical conditions such as Sturge-Weber syndrome, a neurocutaneous disorder involving the leptomeninges. Port wine stains are therefore associated with epilepsy, glaucoma or intellectual disability common in Sturge-Weber syndrome. Additional complications of Port wine stains include a loss of function if near the eye or mouth due to hypertrophy, or glaucoma if near the eyelid.

Skin conditions resulting from excessive epidermal proliferation or inflammation, leading to a production of excessive scales, are referred to as papulosquamous disorders. These disorders can be generalized and localized. Localized causes of scaly lesions include tinea corporis, tinea cruris, tinea pedis, seborrheic dermatitis, psoriasis, pityriasis Versicolor, pityriasis alba, DLE, ichthyosis including Netherton syndrome (a severe form of ichthyosis which is autosomal recessive), and pellagra. Generalized causes include guttate psoriasis and pityriasis rosacea. Hand, foot, and mouth disease is a contagious viral illness that causes blisters in the mouth and on the extremities.

Henoch-Schönlein purpura (HSP) rashes are commonly found on the legs, feet, and buttocks while Immune thrombocytopenia (ITP) rashes manifest predominantly on the lower legs. HSP happens following a sore throat while ITP usually happens following an URTI or Flu. HSP is an inflammation of a blood vessel (vasculitis) while ITP is immune mediated insufficiency of platelets.

Itchy skin conditions include:Allergy & anaphylaxisAthletes footAtopic dermatitisContact dermatitisDrug allergyErythema multiformeFolliculitisImpetigoInsect bites, stings, infestationsKawasaki diseaseLichen planusNummular eczemaPityriasis roseaPsoriasisScabiesTinea corporisToxic epidermal necrolysisUrticariaVaricellaViral exanthemNote: Miliaria rubra is itchy, miliaria profunda usually isn’t.

Sturge-Weber syndrome (SWS), also called encephalotrigeminal angiomatosis, is a neurocutaneous disorder with angiomas that involve the leptomeninges (leptomeningeal angiomas [LAs]) and the skin of the face, typically in the ophthalmic (V1) and maxillary (V2) distributions of the trigeminal nerve. The hallmark of SWS is a facial cutaneous venous dilation, also referred to as a nevus flammeus or port-wine stain (PWS).Signs and symptoms:SWS is generally diagnosed clinically, based on the typical cutaneous, central nervous system (CNS), and ocular abnormalities associated with it.Neurological signs include the following:Developmental delay/intellectual disabilityLearning problemsAttention deficit-hyperactivity disorderInitial focal seizures progressing to frequent, secondarily generalized seizuresIncreasing seizure frequency and duration despite the use of antiepileptic drugs (AEDs)Increasing duration of a transient postictal deficitIncrease in focal or diffuse atrophy – Determined by serial neuroimagingProgressive increase in calcificationsDevelopment of hemiparesisDeterioration in cognitive functioningPhysical signs of SWS are as follows:Port-wine stainMacrocephalyOcular manifestationsSoft-tissue hypertrophyHemiparesisVisual lossHemianopsiaOcular involvement in SWS may include the following signs:BuphthalmosGlaucomaTomato-catsup colour of the fundus (ipsilateral to the nevus flammeus) with glaucomaConjunctival and episcleral haemangiomasDiffuse choroidal haemangiomasHeterochromia of the iridesTortuous retinal vessels with occasional arteriovenous communications

Erythema nodosum (EN) is an acute, nodular, erythematous eruption that usually is limited to the extensor aspects of the lower legs. It is a delayed hypersensitivity reaction to a variety of antigens| circulating immune complexes have not been found in idiopathic or uncomplicated cases but may be demonstrated in patients with inflammatory bowel disease.Currently, the most common cause of erythema nodosum is a streptococcal infection in children and streptococcal infection and sarcoidosis in adultsIn most patients, erythema nodosum is a self-limited disease and requires only symptomatic relief using nonsteroidal anti-inflammatory drugs (NSAIDs), cool wet compresses, elevation, and bed rest.

Based on the patient’s presentation, he’s probably suffering from Leiner’s diseaseLeiner’s disease is a severe generalised form of seborrhoeic dermatitis. It is also associated with recurrent diarrhoea, recurrent skin and internal infections, and failure to thrive.Seborrhoeic dermatitis is a common and self-limiting condition in childhood. Lesions affect the scalp (cradle cap), and sometimes the ear, nose, and eyebrows. It is characterised by greasy yellow or yellow-brown scales.There is an association with Malassezia, and the lesions are a reaction to this yeast, rather than caused by it.It is most common in the 6-12 month age group. Simple brushing with a soft bristle brush, use of oil or emollient, and ketoconazole 2% shampoo are all treatment options.

The skin lesion described is the typical presentation of a keloid scar.Keloid scars extend beyond the limits of the incision.Note:Surgical wounds are either incisional or excisional and either clean, clean-contaminated or dirty. The main stages of wound healing include:- Haemostasis:It occurs minutes to hours following injury. It is characterised by the vasospasm in adjacent vessels, platelet plug formation and generation of fibrin rich clot.- Inflammation: It occurs typically 1-5 days after the injury. Neutrophils migrate into the wound (this is often impaired in diabetes). Growth factors, including basic fibroblast growth factor and vascular endothelial growth factor, are released in this phase. Fibroblasts replicate within the adjacent matrix and migrate into wound, while macrophages and fibroblasts couple matrix regeneration and clot substitution.- Regeneration: It occurs typically between 7-56 days after the injury. The factors that stimulate this phase are platelet-derived growth factor and transforming growth factor. They stimulate fibroblasts and epithelial cells. Fibroblasts produce a collagen network. Furthermore, they cause angiogenesis and thus wound healing.- Remodelling: This is considered the longest phase of the healing process and may last up to one year (or longer). During this phase, fibroblasts become differentiated (myofibroblasts), and these facilitate wound contraction. Collagen fibres are remodelled, and microvessels regress, leaving a pale scar.Clinical correlation:Abnormal scar formation:- Hypertrophic scars:It is the condition where excessive amounts of collagen are produced within a scar. Nodules may be present histologically containing randomly arranged fibrils within and parallel fibres on the surface. The tissue itself is confined to the extent of the wound itself and is usually the result of a full-thickness dermal injury. They may go on to develop contractures.- Keloid scars: This is also a condition where excessive amounts of collagen occur within a scar. A keloid scar will typically pass beyond the boundaries of the original injury. They do not contain nodules and may occur following even trivial injury. They do not regress over time and may recur following removal.

The diagnosis of scabies can often be made clinically in patients with a pruritic rash and characteristic linear burrows. Definitive testing relies on the identification of mites or their eggs, eggshell fragments, or scybala. This is best undertaken by placing a drop of mineral oil directly over the burrow on the skin and then superficially scraping longitudinally and laterally across the skin with a scalpel blade. (Avoid causing bleeding.) Scraping 15 or more burrows often produces only 1 or 2 eggs or mites, except in a case of crusted scabies, in which many mites will be present. The sample is placed on a microscope slide and examined under low and high power. Potassium hydroxide should not be used, since it can dissolve mite pellets. Failure to find mites is common and does not rule out the diagnosis of scabies.

Erythema Migrans is associated with Lyme disease, a tic transmitted infection caused by the spirochete Borrelia Burgdorferi. The rash usually appears at the bite site after 7 to 10 days. It is flat or slightly raised and migrates as the name suggests. Streptococcal throat infection and Crohn’s disease are both associated with erythema nodosum.Herpes simplex and Rheumatic fever may present with Erythema Multiforme and Erythema Marginatum respectively.